I would like to try out some stuff in seven kingdoms 2, because I love the game, and also because (at least I hope) It would make a good starting point for a first project (newer games seem to be more daunting in this aspect).

I have a friend with decent experience of programming in C++, In case we felt like making small gameplay adjustments,
And I myself am a fair drawer (that makes it makes my capabilties sound a bit glorified though ;) ) should we wish to mod sprites

what I mainly wanted to ask here is the following:

there appear to be a few major file types present in the game:
.SPR (the sprites)
.RES (resources)
.FRM ("firm" files)

What tools/software would I require to manipulate these? Is there a modding guide out there somewhere which states what all of these do precisely? Are there any modding forums for seven kingdoms II left open/active (like heavengames does for a few other games for example?

I myself was hoping to try and implement a setting not unlike rise of legends's for the mod ; c'est a dire; a mix of steampunk/arabian nights/sci-fi mayas, and perhaps something out of the scandinavian/Far eastern myths.

If someone could point in the right direction (I'll be looking up some things myself in the meantime), or simply tell me my ambitions are doomed as a first time modder, it would be, very much indeed, appreciated ;)