Editing Attacks

[Shadowwrath5]

Just wondering if its possible to edit the attack properties. The roy I have over rob is amazing and really cool but his up+a is extremely over powered and his charge b is an instant kill on 0 damage. The up+a does 50 damage! I play with a bunch of people who are quite competitive with this game and me using roy in the battle is basically cheating. So how can I fix these two attacks. I like him so much and who ever mad him did very well. Also his final smash is great but big too big is there a way to make it a bit smaller? Thanks