My experience, and may be similar to white bros, I bought the alen ness extension. Two reasons I had to take it to an indie shop:
1. The thread lock on the shock nuts were of such strength that an air wrench was needed to break it loose. I did not have an air wrench. The mechanic BROKE one of HIS socket 90 deg. offsets breaking the nuts loose.
2. A shock press is absolutely necessary, whether you buy it or rig one yourself.
It cost $75 well spent dollars, and saved me a lot of aggrevation.
I'm one to do everything myself. but this one time I let someone with better tools do it.
Did mine with a big C clamp and a vise (White Bros. 2000 FXST) You only have to compress the shock enough to get the lock clip out of the shock body. I had to grind the original shoulder down to get the lock nut off the stud.