13-Now comes the hard part. The seat covers must line up, so count the number of stitched grooves in the vinyl (in our case, seven) and line up the center one (fourth) in the middle of the seat. Start in the front and stretch the material over the seat frame and onto the two spikes in the front. It doesn't look like it will fit, but don't worry. A fter some manipulation, the vinyl will start to give and form to your liking.