How do you change discs on a Ford Focus?
It's a pretty simple task to change the disk brakes on a ford focus.
Once you have the wheels off and the car jacked up ( obviously ) remove the brake caliper ( on most first gens it should be two 7mm hex bolts on the back side of it, might also be a Torx 45 ) one this is off you can simply pop it off, or you can push out the four pins that the lug nuts tighten onto. The disk will come off and you can change it, make sure not to strip the teeth on the pins though. Once the one ones are on simply reverse the steps.
P.s. might also be a good time to change the pads as well.