Spent 6 hours with a helper yesterday and successfully replaced all 4 of my slide toppers.
What prompted the service was one of my toppers released from the coach rail, so rain water was ending up on top of my slide. I would have never known but after a rainy night, I noticed one slide was constantly dripping water all morning.
Got up there and looked and could see the problem clearly, but also could tell that the threads were getting weak in a lot of places on the topper, so even if I reset it - it was going to happen again, or tear elsewhere.
I figured if one is going, they likely all are - so I measured them up and ordered 4 new ones from Stone Vos. They were great to work with, by the way.
Found a great video by the RV Geeks on Youtube - they happen to have the same slide toppers as me. I'm sure there's a video for all the different kinds out there.
Anyway, just wanted to say this was definitely a do it yourself type thing as long as you have 2 people and 2 ladders.
These were the original toppers and they lasted 12 years or so... hopefully the new ones will too!