Before caliper seal replacement, allow the inboard piston(s) to come out so they are easy to remove.
Instructions:
The brake must be fully bled. Remove the pads, install the U shape tool over the front "half" of the caliper body, making sure the thinner leg of the U shape tool is in the pad location.
Pump on the master cylinder until the inner piston(s) come in contact with the tool. Remove the tool and gently remove the piston(s). The outer piston(s) will be removed once bore caps are unscrewed. The caliper will be now ready for seal replacement.
Note:
Both inner pistons need to be pushed into their bores
