This process is a lot of (unnecessary!) work.
But if done correctly, you only need to do the steps 1-4 once.
After that you can simply skip to step 5 each time you want to install another mod.
After this guide you will have at least 3 "Panzer Corps" folders:
- The pristine >>Panzer Corps<< folder at your original install location. This one should be used for playing the official game and DLCs and so on.
- The baseline >>Panzer Corps 1.32<< folder. This one should not be used to play the game, it is simply a baseline folder from which copies are made each time you want to install a new mod.
- The mod-specific >>Panzer Corps xyz<< folder (xyz = name of the mod). Make another one of those for every mod you want to install.
1. If you already modded or changed your Panzer Corps install, you need to make a backup of that install (if you want to keep it) and redownload Panzer Corps:
1a) Go to the parent directory of your existing >>Panzer Corps<< folder (for Steam by default >>C:\Program Files\Steam\steamapps\<< folder).
1b) Make a copy of your old, existing >>Panzer Corps<< folder (eg in a new location like >>C:\Games<<).
1c) Rename your copied >>Panzer Corps<< folder, eg to >>Panzer Corps old<<, to avoid conflict later on.
1d) Uninstall Panzer Corps, so that there is no more >>Panzer Corps<< folder in the original location (for Steam by default "C:\Program Files\Steam\steamapps\" folder).
2. (Re)download and install Panzer Corps in order to get a pristine, unaltered version
2a) If you do this via Steam, the default location of that pristine >>Panzer Corps<< is within the >>C:\Program Files\Steam\steamapps\<< folder
2b) Make a copy of that pristine, unaltered version. Rename the copy for easy identification, eg >>Panzer Corps 1.32<<. This will be the baseline copy for mods.
2c) You should now have at least 2 separate Panzer Corps folders. The unaltered, freshly downloaded >>Panzer Corps<<, a renamed copy of that unaltered version (>>Panzer Corps 1.32<<) and potentially backup folders of previous installs.
3. Update your still unaltered >>Panzer Corps 1.32<< copy to official version 1.32
3a) To make sure you use the right version of the >>Panzer Corps 1.32<< patch, you may download the patch from the link below. Since an earlier version of the 1.32 patch has bugs, but is still around. If you have a Steam install, continue with 3b), for a non steam install continue with 3c):
3b) If you made a copy of your Steam version of Panzer Corps in (2), download the forSteam 1.32 patch from here:
Panzer Corps 1.32 for Steam: https://bit.ly/43Wb2KY
3c) If you made a copy of your not Steam version of Panzer Corps in (2), download the notSteam 1.32 patch from here:
Panzer Corps 1.32 non Steam: https://bit.ly/3P2wE4h
3d) Open the downloaded .zip file, it should contain 1 folder called >>UI<< and 2 separate files: >>PanzerCorps.exe<<, and >>ScenarioEditor.exe<<.
3e) Extract the >>UI<< folder, the >>PanzerCorps.exe<< and the >>ScenarioEditor.exe<< directly into your >>Panzer Corps 1.32<< folder, overwriting existing files. The insides of your >>Panzer Corps 1.32<< folder should look the same as before, but with newer versions of those files.
3f) Start this >>PanzerCorps.exe<< from this install and check that the startscreen displays version >>1.32<< (this info is in the text directly above the "language flags" in the bottom center of the startscreen). This concludes the update to 1.32 and you can exit the game again.
4. Install the >>Generic Mod Enabler<<
4a) Go to the following thread and download the >>jsgme_setup.zip<<: viewtopic.php?f=147&t=27158
4b) Install the JSGME directly into your >>Panzer Corps 1.32<< folder
4c) Run the >>JSGME.exe<< from within your >>Panzer Corps 1.32<< folder and let it create the >>MODS<< folder within your >>Panzer Corps 1.32<< folder
The procedure up until this point only has to be done only once.
5. Make a new copy of your >>Panzer Corps 1.32<< folder for every mod you want to play. (This also helps if you want to play different mods, without having to tinker with the different installs too much).
5a) Copy the whole >>Panzer Corps 1.32<< folder to a new location.
5b) Rename the new copy of the >>Panzer Corps 1.32<< folder, depending on which mod you plan to install, eg to >>Panzer Corps xyz<<, or >>Panzer Corps Modern Conflicts<<, or >>Panzer Corps BE 2.3<< or whatever.
6. Make a shortcut to your new >>Panzer Corps 1.32<< or >>Panzer Corps BE 2.3<< or whatever PanzerCorps.exe file with the /nocache switch to avoid crashes and significantly improve performance
6a) Go into your new >>Panzer Corps 1.32<< or >>Panzer Corps BE 2.3<< folder from the previous step. Right click onto your >>PanzerCorps.exe<< and select >>create Shortcut<< from the menu.
6b) Right click on the newly created shortcut and select >>Properties<<.
6c) Add >> /nocache<< at the end of the destination path within the properties of the shortcut (eg if the old destination path reads >>"C:\Games\Panzer 1.32\PanzerCorps.exe"<<,
then new destination path should be >>"C:\Games\Panzer Corps 1.32\PanzerCorps.exe" /nocache<<)
Picture from the original post in McGuba's Battlefield Europe thread (Win 10/11 looks like Win 7):

7. Download the desired mod and activate it using JSGME.
If you struggle with my following short guide how to do that with JSGME, additional info on JSGME can be found here: https://www.slitherine.com/forum/viewtopic.php?t=27158
7a) Download the mod. This should provide you with an archive file (eg .zip) containing that mod.
7b) Extract the relevant files from the downloaded archive file into the >>Panzer Corps xyz\MODS<< folder (eg >>C:\Games\Panzer Corps xyz\MODS<<).
Most mods only provide one relevant folder within their archive. Some larger mods provide several folders, where you have to choose what is relevant for you (in that case the mod forum thread may provide additional information).
Eg for installing Battlefield Europe 2.3, the downloaded >>BattlefieldEurope23.zip<< archive contains 2 folders and 3 other files. Of those, extract only the >>Battlefield Europe v2.3<< folder into your >>Panzer Corps xyz\MODS<< folder.
Thus your >>Panzer Corps xyz\MODS<< folder should then only contain one folder called >>Battlefield Europe v2.3<<.
7c) Start the JSGME.exe file within your >>Panzer Corps xyz<< copy.
7d) You should see your previously downloaded mod from step 7b) in the left field ("Available Mods:"). Click on it to mark it, and then click on the top button ">". This activates the mod (and transfers it from the left field to the right field called "Activated Mods:").
7e) If you want to update a mod, deactivate the existing version with the "<" button. And then activate the updated version with steps 7a) to 7d).
If you eg have successfully installed my "Locarnus Addon to Battlefield Europe" mod, it should look something like this (since it depends on having "Battlefield Europe 2.3" installed as well). Though instead of having a distinct name for the path (like >>Panzer Corps xyz<<) it is simply in a different location than my pristine >>Panzer Corps<< copy and my baseline >>Panzer Corps 1.32<< copy.

It is advisable to have different >>Panzer Corps xyz<< folders for each mod you want to play simultaneously. You may start from step 5 for each additional copy you require.