Keep in mind that the clips need to be put on the "outside" (or rearward) (hooked) side first, then the longer, forward side slides down until you hear it snap. If you install long side first, you will bend and curse everything until you have damaged something.

I always start at the middle first and wirk my way to one side, then go back to the middle and work to the other side. Then go back and snap the inner trim snaps last, and re-tuck the seat flap and front edge corners into the pockets.

Taking the boot off is reverse order, and you need to slide your hand under the boot at each clip and pop the front (long) side upward first, then unhook the hooked side of the clip from underneath. New clips can bloody your fingers until they are broken in a bit.