I installed them on my -8 and it wasn't hard at all. If there's a trick to it, and it's not much of a trick, you have slightly different locations on either side of the cowl. Pay attention to the measurements given in the instructions. I used 8.9 oz harness fiberglass cloth to back up the nut plates you'll install. I used three plies and should have used four if not five, so there's some learning! They work fine and look good.
You'll need to remove a couple of the hinge eyes to make room for the covers.