The trick is to work from front to back and do both sides as you go. That's how I did it and I've had to do it a couple of times ( denser foam ). Pull it tight but not so tight it makes waves in the foam. I also sprayed the seat pan with adhesive. I've logged lots of very hard miles on this and I love it! don't forget to put the plastic thing on this and here too here's a back shot it really isn't hard, just take your time and keep checking to make sure it's even.