I have replaced 2 top inserts-on 36 1603 and 32 54 7 passenger. Best advice is to lay material outside on a driveway in the hot sun for several hours. This makes the material soft and pliable and easier to stretch. Leave at least 6 inches extra to be able to grip the material and a helper would be welcome. Mark the front and rear midlines and do this first as tightly as you can reasonably do. Then do the sides at the halfway point. Then triangulate untacked areas symmetrically until tacks are about one half inch apart. ! would put a bead of silicone under the material and then a strip of masking tape after you have trimmed excess and before the hidem. This can protect paint from needing cleanup. Ok to place a thin bead at edge of material but such that can be covered up by hidem. After hidem is tacked place a bead of silicone insied the hidem and covering the tacks. Both my inserts look good and I saved several thousand dollars doing it myself. Really not a difficult job but warm material a great help.