I think the wiper has been put on slightly high, because when in use, the blade goes onto the tailgate paintwork at the left hand side of the sweep.  How does the arm come off so I can re-position it on the spline please?

Had this problem when the dealer replaced my rear screen and refitted the wiper arm incorrectly.  You need to lift the flap which covers a securing nut where the arm fixes to the wiper motor (left hand side of wiper arm).  Then remove the securing nut, pull the arm off, refit it correctly and do up the securing nut again.  A five minute job.

1 hour ago, nbramwel said:

Had this problem when the dealer replaced my rear screen and refitted the wiper arm incorrectly.  You need to lift the flap which covers a securing nut where the arm fixes to the wiper motor (left hand side of wiper arm).  Then remove the securing nut, pull the arm off, refit it correctly and do up the securing nut again.  A five minute job.

Thank you, very helpful.

@Trev2 Did you manage to re-position the rear wiper arm easily?  Mines the same, it's a notch too high! I tried to pull the cover off by hand but it's really stuck on there. If you did get it off, any tool suggestions... technique?

Yes, no problem, I just followed @nbramwel 's instuctions.  The wiper arm was a bit stubborn coming off, but a broad blade screwdriver under the arm and a few taps with a nylon hammer sorted that without any damage.  A couple of dabs of copper grease on the spline should help if it ever needs to come off again.

@Trev2 Cheers for the info! One thing I just noticed is the heating filaments are doubled up where the wiper rubber is meant to sit directly over. I guess this is to heat it up to un-stick when frozen. Mine is perfectly inline with these filaments so I won't bother touching it.  Well for now