Master Cylindar Rebuild

Good Morning! I recently inherited a 1995 Polaris Magnum 425 4×4 that is in fair condition. I have gotten it running and installed new brake pads. I bought a master cylindar rebuild kit and am beginning this adventure. My question is how do i get the piston out to replace the seals on the piston? I have the cylindar off from the handle bars and drained of the brake fluid. It is still attached to the brake line and such. Thank you for your responses.