Hi, You Need A Set Of Metric Hex Sockets, It May Be A 7 or8 mm.I'm Not Sure Of the size. Put It On A3/8 Rachet And Remove The Two Bolts, And Remove The Caliper, Push The Piston Back Slowly With A " c" Clamp, Before Installing The brake Pads Put A Light Coating Of Brake caliper Grease To the Caliper, Where The Pads Contact The caliper. Also Put A little Coating Of caliper grease On The two Bolts You removed. Push the Bolts out enough To Put The Grease On them. This Is what Keeps The caliper Sliding. Now Install Brake Pads And Reinstall Caliper And Tighten Bolts.