Looking to mod a PC Game (NFL Blitz)

[djsteveo627]

I apologize in advance if I sound like an idiot right now, I have never modded a game and am looking to mod the PC version of NFL Blitz. I downloaded a roster editor from nflblitzfans and would like to make some other updates. There are two folders in the iso, one titled "data" which is a bunch of .wms files and one titled "sound" which is a bunch of .bnk files. Could someone assist me in viewing and/or editing these files? I'm not trying to do anything crazy, just changing colors of helmets/uniforms or replacing logos. Would also want to remove or modify some of the announcer audio files so that they say the correct player names when I update the roster. TIA