You need to cut a nice round hole a little bit bigger then the bolt hole in the upholstery. You need to put a plastic washer between seat bottom over the upholstery and the arms from back rest so it doesn't bind up when you fold seat back forwards. Ask your upholstery shop for them. It could rip and ruin your seat upholstery if you don't install them. . If you have any other questions ask I have been doing upholstery for over 30 years. Tom