How to edit a SNES rom

[Korkmaz]

Does anyone know how to change a smc file?

I'm playing Super Tennis, so is it possible to change colours, names, etc etc?

[Lefteris_D]

That's called a rom hacking. Not exactly what somebody can teach you in a night I'm afraid. You will need to do your research.

[alcoatjez]

Check RomHacking.net (http://www.romhacking.net). It has all the info you need. If you're lucky, there is already an editor for it ;)