Remove the reservoir cap and drain the brake fluid into a suitable container.
After disconnecting the mounting screws, pay the reservoir free from the master cylinder.

Using a snap ring pliers, remove the retainer ring.

Remove the primary cylinder pin. Push the primary piston with a screwdriver and remove the primary piston assembly.

Remove the secondary cylinder pin. Push the secondary piston with a screwdriver and remove the secondary piston assembly.
Do not disassemble the primary and secondary piston assembly.