A couple additional tips that may help a beginner. Someone mentioned caliper slides, that doesn't apply to the rear calipers so disregard. You may find it difficult to push the pistons back into the calipers to get enough room to fit the new pads. You can do either of the following: 1) take off the cap from the fluid reservoir on the master cylinder, put a paper towel under the cap and then barely screw it back on (maybe 1/2 turn) - this allows fluid to be pushed back into the reservoir and will absorb some spillage as the level rises while you're pushing the pistons in. Or 2), as someone mentioned, open a bleed screw and have a tube into a container to catch the fluid that comes out as you push back the pistons(spray plenty of PBlaster on the bleeder - do not apply too much torque to a stuck bleeder or it will snap off). For actually pushing the pistons, if they're stubborn I recommend unbolting the caliper from the axle, suspend the caliper with a hanger or whatever you like (do not disconnect the brake line and don't hang the caliper from the brake line), then apply a C clamp directly to the piston so it's being pushed straight into the caliper (you may want to put one of the used shims on the face of the piston to protect it). Don't pry on the piston with a screwdriver to lever it against the rotor - yes it takes a few extra minutes to unbolt the caliper but a stubborn piston will retract much more easily with this method unless you have a C clamp that's a good fit without removing the caliper. Once the new pads are in, drive the new retaining pins (one set of hardware typically includes 4 pins and 2 springs total to do both sides) all the way so the head is flush with the caliper body. If you don't, they'll slide out. I found out the hard way. Be sure to look at the spring before you remove it so you know how the new one goes in (slide it into place before driving the pins all the way in).