If the measurement is under service limit, replace the piston.

Piston Diameter
Standard: 75.959
75.974 mm
(2.9905
2.9911 in.)
Service Limit: 75.81 mm (2.985 in.)
Cylinder (Upper Crankcase) Wear Inspection
Piston Ring, Piston Ring Groove Wear InspectionCoupling Bearing Removal
Remove:
Coupling
Grease Seal
Circlip [A]
Special Tool - Inside Circlip Pliers: 57001-143
Remove the bearing [A] by tapping from the wheel side.
Special Tool - Bearing Driver Set [B]: 57001-1129
...
Operational Cautions
1. Do not put two keys of any immobilizer system on the same key ring.
2. Do not submerge any key in water.
3. Do not expose any key to excessively high temperature.
4. Do not place any key close to magnet.
5. Do not place a heavy item on any key.
6. Do not grind any key or alter its ...
Front Brake Pad Installation
Check that the pad spring [A] is in place on the caliper.
Push the caliper pistons in by hand as far as they will go.
Install the brake pads [A] on the pad spring correctly.
Fit the pad into the groove of the caliper as shown in the
figure.
Install the pad pins while pushing t ...