seized caliper, any hope?

[capedoryus]

I have the front drivers side caliper off and used air from a bike pump to get one piston out of the caliper but cant seem to get the other one out. I put the cleaned up piston back in and secured it so that the other piston(the siezed one) would be the only one able to move from the air pressure. The piston just aint goin anywhere. any ideas on how tto get the piston out of the caliper.
Thanks in advance
JOhn