how to turn a 2 button char into a 3 button char

[x_mad80]

i'm sure this as been asked before, but how do i do it?

i looked through the tutorials section could'nt find aything. or if there is a tutorial i'm just blind i guess.

what i mean is to add a strong punch and a strong kick to a char that has  only a weak punch , medium punch ,
weak kick, and medium kick. (including jumps and crouch attacks)