Right,
Seen as somebody has asked the question and I had some black vinyl wrap sat in the garage that I was planning on using on my wing mirrors thought it was about time I got round to it. here's how I went about it:
First of all adjust the mirror so that there is space to get behind the mirror glass (make sure it is as shown in the pic and not with the gap nearer the window side of the mirror or you may damage the wires for the heated glass when removing it)
I then simply get my thumb behind the glass and prise it off taking care to push/pull as close to the clips as I can.
With the glass removed the 2 wires need to be unplugged from the glass (I took note of which wire went where but not entirely sure if it matters seen as it's only a heating element)
Once the glass is out of the way the 2 clips towards the top of the casing can be un clipped with a screwdriver (one of them is circled green in the pic but they are easy to spot as they should be the same colour as your mirror cover as opposed black like the rest of the casing) With these 2 clips undone then there is another small clip hiding away behind the pivot that holds the part of the cover that sits just below the LED strip (this is circled red in the pic) once you have pushed that clip with a screwdriver then prise off the
lower part off the mirror casing (I used a thin plastic body filler scraper to prevent damaging the paint/ plastic)
Right now that is as far as I have got I haven't come to put them back on yet as I've just spent 2 hours of my evening wrestling with a sheet of vinyl wrap getting it to go around that stupidly awkward shape (I'm quite happy with it though for my 2nd time playing with vinyl wrap) just got to do the other one in the morning.......