Goody, they can be put on by one person, but unless you know how, it can be somewhat difficult. If you have a full van like mine, you need to get on a step ladder. I'm 6' tall, slim and reasonably agile and for me on my own it was not an easy job, stretching me to my limits.
I'll explain how; What I did was lay it down on the ground face down, (the side to the van on the ground) then fold the sides to the middle and fold again to the middle etc until you have a long cover about a metre wide. then roll it up from the front to the back.
Once you have that, put it on the roof at the rear of the van, and unroll enough to hang down the back with the rest of the roll on the roof at the rear. What I then do was give it an almighty heave to unroll it so it hung over the front of the van. My aircon usually stopped it, so I had to reposition the ladder and feed it over until it hung down at the front.
Then you start to unfold one to the left and then one to the right until the sides hang over. If you have any sharp edges cover them with some foam so the cover doesn't rip.
Having said all of this, I no longer use my cover as it created a bigger problem than it was worth. About 12 months ago, we had a week or so of over 40 C days. The next time I went in the van I found the inner roof lining over the bed where it start to slope down to the front "popped" for about a metre or more at the join. The staples had given way.
My only explanation was the excessive heat built up inside the van with the cover on. I now leave the small kitchen window and ensuite windows on their first lock on the catch and the roof hatch open about an inch to let the hot air escape.
Unfortunately I don't have either but the best cover is a garage or at least a carport. I'll never use a cover again. It took a bit of work for me to repair the roof and at that time the van was only 5 years old.