all extreamly simple, rear bumper is held on by 2 13mm bolts(i think, may be 15mm) on the inside of the boot and the 2 screws on the edge of the bumper in the arches on each side, undo all that and just pull the sides of the bumper away from the arch and it comes off, re fit is the reverse
can be done in 10 mins! front bumper is pretty much the same, 2 screws on the arches and the 2 13mm bolts on the inside of the engine bay but the one on the left hand side of the bay by the ps bottle or the alternator end of the engine can be a pain and you may have to remove the carbon bottle thing but thats not to much of a problem and is held on with 1 bolt 
(undo these from under the car, so jack it up and put it on axel stands)exhaust backbox is easy, just undo the clamp on the old backbox clamping it to the centre pipe and then pull it off, if its tight then give it a tap with a soft ended mallet
then refitting, put some exhaust paste around the joint where the backbox fits onto the centre pipe and slide the new backbox over the centre pipe and fit a new clamp onto it tighten up and job done, again can be done in 15 mins wheels, liturally jack the car up take the old wheel off and fit the new one on and tighten up.
job done i think you could easyly do all of it in a hour.
