Hardest part is getting the retaining clip back in again as its pretty fiddly.
In layman's terms
Take wheel off
Pry retaining clip off
Undo caliper bolts (the ones with caps on) Remove caliper and pads (support the caliper with something so you don't put tension on the brake hoses
Push piston back, it just goes straight in
Remove caliper carrier (2 larger bolts)
Remove disc (undo the "pointy" bolt, might need to take a hammer to the disc if its rusted on)
Put new disc on and put bolt back in
Reattach caliper carrier
Fit new pads and put caliper back in (making sure you copper grease everything except the braking surfaces) put bolts back on
Refit retaining clip
Put wheel back on
I've got Tarox drilled and grooved discs (the sport japan ones) and Tarox pads on mine, they are pretty pricey but seem very good. In truth though the drilled and grooved discs don't really do much other than look pretty.