Yep, took me and my girlfriend ages to get it on the first time (that sounds a bit dodgy). Second time was heaps easier, now with two of us it's literally 5 minutes up or down. On your own a few minutes longer.
To make sure it clips in, we do up the front latches fully as the first step, as sometimes they'll come unclipped during the process and you won't be able to get them on at the end.
You'll also pick up tricks to make the windows easier. Make sure you zip them up only an inch or so, then push them into the door jams, close the door, and do the rest of them up.