Its pretty easy to remove, you just pull down and/or to one side (this requires a lot of effort).
I would suggest replacing it with an auto-dim mirror with homelink from a newer C- CL- SLK- etc. mercedes:
http://www.2phast.com/500e/mirror.htm
The installation is quite easy, the mirror base of the newer mirrors match the w124 base and then you only need power and ground to make the auto dim and homelink controls work. I picked up a nice, used black mirror from a 00 C230 on ebay for about $30 shipped. You can usually find them for around that price. IMO its a great, cheap upgrade!