Hi so I had bought the HD turn signal cap extensions P/N 71500179 and after researching the forum was pretty much terrified to try the job myself, but the wife is away for the weekend and it was a cool morning so I ended up giving it a shot. Despite the instructions here is what I did (both sides):
- two screws out holding the switch clamp around the bars
- using a small and a medium flat head screw driver decided to basically pry the old caps off (so what if they break - one did) - most leverage was from the non-pivot end and a some from the top (I did not remove the tiny switch screw)
- to put the new ones on, I first lightly filed the leading edge (which is already beveled - got that tip here)
- then I put a half drop of 3 in 1 lubricant on the posts (one smooth one splined)
- then I held the cap next to the switch housing and held a hair dryer on it for a couple minutes
- then I gently worked the cap onto the posts, being careful to have the cap and splines lined up correctly

Presto, after months of wondering if I should try it or not the whole job was done in an hour or less. I'm pretty pleased with my old self.

 

Nice, I'm looking at getting a set of those myself!

 

My experience with changing the switch caps is this; the stock black caps were removed easily. I installed the chrome switch caps which are slightly thicker and less flexible than the stock caps. The chrome caps installed easily and a drop of lubricant did help. But, get it right the first time. The chrome caps are not removed easily due to their reduced flexibility, even heated. So make sure each cap is in the right place and right side up.

The new extended turn signal caps are very nice. It is much easier to activate and deactivate the turn signal... less thumb reach.

 

Easier to get the stick-on kind.

 

I replaced mine also. Have relatively small hands and I'm very pleased with the extensions. Makes it so much easier to hit the switches now.