FleetwoodCouple, I changed out the topper on my big slide which was like twenty some feet long and it is fairly easy, but my wife did help me while I sliding the material out of the guide she would hold up the other end.
Just make sure you pin both ends so that the spring does not unwind on you. I used two allen wrenches to pin the ends.
On Goggle they have some real nice videos that will take you step by step on how to do it.
I ordered the material and within a week I had it. Now I am getting ready to do the smaller slide in the bedroom. That should be a piece of cake. I could probably do that myself.