pushing the pistons with your fingers, good luck. Go down to Autobahn and they have these plates that pushses the pistons back that allow you to put in the new pad. Once you change them with that flush out the brakes because you will have air in them. Thats it.
dont put it in yourself. It best that the computer is put in by a mechanic and tuned straight away. I know someone that put it in himself with a new set of forged pistons. He drove it for a while untuned and bye bye new forged pistons.
my 2 cents