I think the only Pokemon romhack I played was TouhouMon, I forget if I had to use another software to patch the FireRed rom itself for it or if I just had a pre-patched rom for the game but after that you just run it in VBA
looking up Infinite Fusion, the installation is a batch file that downloads the game from its github for you and as far as I can tell just run the EXE from there to play
http://gmun.moe/ffcc
GuessMyUserName
's account's very own account!