its tricky, but not hard
there is 4 large bolts under rubber plugs in the back of the car(indside near spare tyre) and 1 bolt on each side in the inside also, then 2 bolts in each wheel arch small ones one on bottom edge one on inside edge of arch, aswell as losing your mudflaps, it will come out all in 1 piece
there is NONE under the car.
* oh just re-read, the ones under the plugs must be the ones your having trouble with, get a piece of steel tubing to fit over the end of your wrench to lever it with, should come off WAY easier, thats if your socket reaaches it! good luck