Non-Electrochromatic mirror removal procedure here:

Non-Electrochromatic Mirror Removal (First Section)

The Electrochromatic Mirror is removed as follows:

This one is quite easy but a little bit fiddly.....do you have a mirror that looks like this?:

As can be seen, the liquid between the two layers seems to have moved around a bit! I bought a second-hand one from Germany (around 40) which wasn't bad as BMW wanted close to 200!

The mirror glass-assembly is held in place with a rotating collar. You can see a little 'spike', this points towards the bottom of the car:

Use a thin metal blade of some sort to get between the housing and the glass assembly and push the spike in this direction:

Press on the edge of the mirror assembly and it should pop off the housing. If it doesn't, move the spike back a bit and try again. You can gain a bit more access by pressing the top of the mirror assembly so that the lower edge pops out a bit. Once you have the spike in the right place the mirror assembly will pop off the housing. Remove the two heater wires from the rear of the assembly:

If you have the Electrochromatic glass there will be a connector at the edge of the glass. Disconnect this as shown:

That will release the old mirror assembly.

Start fitting the new assembly by mating the Electrochromatic connector and push the connector pair neatly back in the metal clip:

Connect the heater wires to the new assembly, I don't think it makes a difference but the BROWN wire was at the top.

My new mirror assembly has a slightly different collar without the spike but with a hole instead:

However, fitting is just the same, after the wires are connected push the assembly onto the circular mount and then move the spike (or hole) towards the car and it's fitted!

Although there are two different part numbers for RHS/LHS there is no difference apart from the orientation of the locking ring. The locking ring can be removed by lifting slightly above the stop and moving the ring further clockwise where it will pop off upwards.

The plan is to get the spike at the bottom of the glass for whichever side the glass is used on:

I thought I would have a go at seeing what happens when you stick a few volts in the Electrochromatic wires......before:

....and with a few milliamps of current (40mA - voltage drop 1.9V):

What happens if you stick more current in? Well, it sizzles and black stuff squirts out:

That's probably not a good thing!

All done, time for a cup of tea