How to change a convertible top
Things You'll Need
Fix small rips, tears and slits less than 12 inches long in convertible soft tops using traditional sewing techniques. Take the extra time and effort to sew up longer tears, or replace the top to avoid an unsightly seamstress' scar. Get some heavy-duty upholstery thread and match it to the car's top as closely as possible. Use a large, curved, upholstery needle to sew the torn canvas, leather or vinyl neatly back together.
Take your time sewing. Work with the top up, so that the fabric is stretched taut. Thread the needle and tie on a length of thread longer than the tear. Keep the stitches in a straight line and pull the thread tight for a tidy seam. Place the stitches at least 1/4 inch away from the edge of the rip, so that the stitches don't pull out and cause further damage to the soft top.
Tape over the underside of the sewn seam from inside the car. Use duct tape or any wide, stiff tape to catch excess glue. Glue the top of the seam from the outside of the car with fabric adhesive. Waterproof the repair job with marine canvas. Cut
the canvas to overlap the stitches and sew in the patch. Seal up the edge of the canvas patch with seam sealer to prevent leaks. Use the seam sealer on any tiny cracks where the top folds, to prevent water seepage.
Diagnose a convertible top that fails to operate by locating the roof's pump and motor. Check the wiring going into the motor for corrosion or shredding. Make sure the black ground wire is connected to the car body. Take the motor apart and inspect the brushes, armatures and wiring. Look for burn marks caused by shorts. Check for corrosion. Replace the worn-out parts, or take the motor to an electrical motor repair shop if it needs to be rewound. Get a new or replacement pump or motor if the old one is shot.
Rebuild, replace or repair all motors at once, if your car has multiple motors. If one has failed, there's a good chance the second or third one is ready to go out. Make sure the mounting holes line up if you buy an aftermarket convertible top motor. Cut and splice the wires and make sure that no hoses are kinked, if the connections don't exactly match up.Source: ehow.com