Remove the lining in the boot which is held on with one screw and a dozen poper clips, on your wiper blade there should be a cover with a nut behind it which will remove the wiper but will need a good tug.
On the inside the motor will be held on by either three bolts or torx screws. (Can't quite remember), disconnect the motor which is just plugged in and some brute force is needed to remove it as its Abit like a ball joint so I would suggest getting someone to hold the tailgate while you pull.
Once off, get a bling grommet and fill the hole, the size needed is 13mm iirc which you can get from halfords for 60p
hope this helps.