I had a surround replaced on my Xplorer after the gas strut mountings ate holes in it.
I took the caravan to a dealer with a workshop filled with strapping, healthy fellows. It took as many as could fit inside the caravan all their strength to remove the old surround. And almost as much to get the new one in the tracks.
The surround is easy to get and not very expensive either, but I don’t suggest you try to change it unless you have access to 8 or 10 very strong assistants. It takes immense muscle power to pull that canvas through the guides, and it’s incredibly awkward to pull sideways the way you need to.
BTW the new surround already had holes chewed in it by the same strut mountings by time I got home.