2011 Polaris Ranger RZR ATV Service Manual, Page 336Get this manual
BRAKES Caliper Disassembly
12Remove both brake pads from the caliper (see "FRONT BRAKE PADSPad Removal")Remove mount bracket assembly and dust bootsIMPORTANT: Do not remove the caliper pistons with standard pliersThe piston sealing surfaces will become damaged if standard pliers is used5Once the pistons are removed, use pick to carefully remove the square O-rings from the caliperO-rings should be replaced during caliper service