It's not difficult to put together, although it is much easier with two people doing it. We had issues also with trying to fit everything into a relatively small space - had a Bowflex at the time and a spinning bike. Basically, if I remember right, we had two 4x8 sheets of plywood - took some time to glue all the little blocks a couple of inches apart - there's a lot of blocks! Then you have to turn them over carefully, without knocking the blocks. Then, you fasten them with those hinge things (can't remember what they're called - my husband used small screws and a drill I think - they were flush though and not sticking up. Then you put down the double-sided tape and get the vinyl flooring on - this too is heavy stuff and is best done with two people. But once it's in place, you are set! It also can be moved, again easier with two people. We have dislodged some of the blocks over the years with all our moves, but still there are plenty left and can be easily reglued.
Hope this helps,
Colia