How do you make mods for supreme commander forged alliance?

I'll try to point you in the right direction. The making of mods varies, but basically what you do is make changes to the standard game files. I do not know the specifics but these files are later compiled into a single data file and placed inside the mods folder so they can be activated. If you browse some of the major forums you can probably learn a few things. Most modders will be more than happy to point you in the right direction. Hope this helps.