I hope this helps. There is a nut at the base of the arm.
Tailgate wiper arm
Removal
Operate the wiper motor, then switch it off so that the wiper arm returns to the at-rest position
HiNT
Lift the cover from the base of the wiper arm and unscrew the retaining nut.
Lift the blade off the glass, and pull the wiper arm off its spindle. If the arm is tight, use a suitable puller to release it from the spindle.
Refitting
If removed, refit the wiper blade to the arm at this stage. This will prevent any damage to the rear window from the upper end of the arm.
Ensure that the wiper arm and spindle are clean and dry, then refit the arm to the spindle and align the blade with the previously noted rest position.
Stick a piece of masking tape on the window, along the edge of the wiper blade, to use as an alignment aid on refitting.
Refit the spindle nut, and tighten it securely. Close the cover on the base of the arm.
koter002
March 2009