I did this mod the other day on a 2006 330xi, production 12/05(dec 2005).
Removing the trim was much easier than I anticipated, although due to what I assume was the very low temperature (20c) one of the blue trim plugs with the oval metal capture rings broke in half releasing the metal ring still attached to the post on the trim that plugs into the dash. That is a complicated and probably incorrect explanation but the point is to be extra careful if it is quite cold and take your time. For me the breakage was not a problem I was able to put it back together and it is held flush and proper.
Another note was difficulty I had separating the switch from its housing. This caused huge frustration to me until I grew so angry I manhandled it with herculean strength, to which it responded by cleaning disconnecting. Just make sure to press the tabs in while pulling, it will come apart with enough force.
Most notably, I did
NOT have to fabricate a switch (although I already had before starting) as the white plastic connector was already there, all I had to do was release the face of the button, cut the little tabs off of it and put it back in. No extra parts required. Removing the button face was not so bad, just use a small jewelers flathead and be judicious with force given its size.
One last important note I am surprised is not mentioned here more. Once you have completed cutting the tabs (+ installing a homemade connector if applicable) and are reassembling, pay particular attention when you put the entire switch back into its housing. When you put the switch into its housing you may hear a click, but in my case the clips HAD NOT actually clipped in place and required substantial force to get them to snap back in place one by one. I almost did not notice this, and if I hadn't then the entire switch face would have pushed into the housing if I pushed on it to activate the lights once I re installed it into the car.
I haven't used the fog lights but they are there and it was a very easy mod.
