I want to make a mod like this https://www.nexusmods.com/dyinglight/mods/184
But I don't understand what they changed to give you 4 upgrade slots I want to make a mod that gives you 10 to 20 upgrade slots on all weapons if possible

Also how do you know where to look for the specific file you need to edit like for example if I wanted to make a longer a grapple hook distance mod how would I know where to look do I just need to study every file in Data0