Is there any way to create minor texture hacks?

[Crazy Hand 2001]

I want to retexture Mario's blue costume so it looks like Ice Mario from NSMBWii, replace his brown costume with Flying Mario from Super Mario Galaxy and change Green Kirby to his Smash 64/Melee design

 

[Pyro Gaming]

I want to retexture Mario's blue costume so it looks like Ice Mario from NSMBWii, replace his brown costume with Flying Mario from Super Mario Galaxy and change Green Kirby to his Smash 64/Melee design

1. Open the costume in BrawlBox
2. Expand TextureData[0]
3. Right-Click the texture you want to replace and hit export
4. Edit as you wish
5. Open the costume again
6. Go back to the texture you want to replace
7. Right-click, replace
8. Select your custom texture and hit okay
9. Save as archive pair in the proper directory and boot up your game