I just did this job and it took all of 90 minutes for both mirrors, thanks to all the information on this post. I bought a pair of earlier "Bolshevik boots" that were more pliable so maybe it made the job that much easier.
The mirror easily came off with three screws after removing the interior triangular piece. The electric plug on the passenger side was held on with a tiny center screw.
I began by removing all the old petrified rubber. Then, starting at the bottom of the mirror, I popped the end of the side trim off with a screw driver and simply worked my way around to the top until the whole trim piece was off. That left the front cover which only took a few seconds to pry loose.
I used a heat gun prior to installation, holding it a few inches away for about two minutes and constantly moving around the whole boot to soften it up. It slid right on from the outside (end opposite the mounting frame) and I was actually surprised that there was hardly any stretching effort to get the boot onto the triangular frame. I used a flat-head screwdriver over the sharp tip of the triangular frame to prevent it from tearing the boot as I stretched it over. Once the boot was on, I installed the gasket, side trim piece, then the front cover and it was ready to reinstall on the car.
So, I think that for the short time it takes to remove the side trim and front cover, it is definitely worth the effort.