For starters, the gripper seats are awesome!

Install can be somewhat tricky if its your first time.
Finally, my short lived upholstery career comes in handy.
-Remove old cover and all staples. A sharp pair of side cutters works well for this.
-Center the cover and flip the seat over and place a couple staples in the front and rear to hold it snug and in center...You may remove and adjust these later.
-Do the same to the longest areas of the sides ensuring to keep the cover tight and centered...May readjust these as well. These are just anchors for now.
-Continue stapling to your four corners. Make sure your seams stay straight and the cover is snug.
-I always found it easiest to leave the corners for last as you can more easily remove remaining wrinkles here.
*Pull it tight enough to bring the wrinkles to the underside of the seat. More staples = less wrinkles. Don't get to crazy though. Those staples add weight.
Hope that helps a little anyway.