I have a TT that does not allow walking on the roof.
We lay the cover on the driveway, the side are spread out, then we roll both end towards the middle so we have a long tube. We flop the tube in the middle of the TT roof and roll it out towards each end, my DW on a ladder on one side, me on a ladder on the other side.
The only difficult part is unrolling over the AC shroud. It is a pain no doubt but unrolling and dropping the sides takes about a half hour.
There is a bit of prep work as we have to pad the gutter spouts and any sharp edges. After the cover has been put on place, I get the honors of crawling under the TT to connect the straps.
I use the cover to keep the snow and rain off the roof. Other do not feel TT covers necessary.