Remove the OEM c-pillar and lower window molding. This is accomplished by removing the interior plastic panel around the window. This panel comes off by removing the seat belt bolt and coat hanger screw. There are two or three plastic fasteners that help secure the piece and are easily detached. Remove the panel and you will see bolts for the c-pillar. A swivel attachment is recommended for easy removal of the aft bolts. Then, pull down the window weather stripping above and around the door, then remove the weatherstrip mounting strip (torx bit) and underneath the strip you will find small philips screws that hold on the a-b pillar molding. (there is small section of OEM c-pillar that extends under the a-b pillar molding.) Once loosened the c-pillar panel can easily be removedFitment:We recommend a test fit of the panels before paint. Many cars differ slightly at the ab-c pillar junction at the top as well as the door molding height. We provide the panels "big" in these areas so that you can achieve a perfect fit. Shaving these areas with blocked sandpaper will allow you to accomplish a ZERO tolerance fit. Your new JMS Products Inc. C-pillar kit installs in minutes. Be sure to transplant the weather stripping from your stock panel to your new custom made Retro C-pillar panel. This is the strip along the top of the panel that runs along the rear window. This can be easily pulled off the stock piece and attached to the new panel with a silicon adhesive or RTV. Install the piece from bottom to top. Insert the panel onto the 1/4 panel molding seam mount while holding the top of the pillar toward you. Be sure this seam is parallel with the window. This metal lip tapers slightly toward the window and in most cases needs to be straightened. This can be accomplished by using a pair of seamers. Once the panel mounting rail is in place push the top of panel against the car. The bolts will slide into the original OEM mounts( the first bolt hole on OEM Mustangs will need to be bored to match the other 4 mounting holes) Before tightening the bolts for the pillar, seat the rolled front edge of the panel in between the window weather stripping and the b-pillar window frame. This kit installs over the 1/4 window and does allow the scoop to made functional if you decide you want to remove the 1/4 window. Please contact JMS Products regarding this modification. Please run a bead of RTV or silicon on each washer and slide over the bolt before installing the nuts. This allows the washer to be firmly held in place while installing the nuts and prevents the nuts and washers from loosening over time from vibration.Prep and Paint: Prime and Paint w/ Flex agent. ( We recommend the use of a urethane primer / sealer or epoxy primer before paint for best results) If your paint is metallic use 600 wet final. If non metallic 400 wet for final. Our panels come gel coated and will require primer and fine wet sanding as does any body part. Be sure to instruct your paint shop to exercise extreme care if baking the paint as excessive heat will damage the panels.Improper preparation of components will cause the warranty to be null and void.Seasoning: Prefit and install your panels prior to painting. Allow the panels to be on the car for 10-14 days before painting and be sure to expose the parts to different climate conditions. We provide a full warranty on our products and since many of our parts are "fresh" we require seasoning any fiberglass/carbon fiber body part we produce. If a part is not seasoned and sprayed while "fresh", waving could occur as the fiberglass resin and resin based materials used will contract slightly over this period.Void of Warranty: If seasoning time is provided and a defect occurs, we will gladly replace the affected part free of charge and we will make concessions for paint cost. If a part is not properly prepared or mishandled during the prep / install period the warranty on the product warranty will be void and we will not make concessions for paint cost.