It's for the DC5 but its pretty much the same with the EP3 and most other cars.
Basically, jack car up, take wheel off, remove two bolts and it should come off. Putting it back is just reverse. Hardest part is just getting those bolts off, may help to turn your wheel to one side. Make sure when you assemble it back, that those bolts are tightened to specs (or just really tight...)
Oh and you shouldn't need to push the piston back in unless your changing your pads.