The Mustang GT is almost always equipped with a rear spoiler, unless it's a convertible model. Other Mustang models may or may not be equipped with a rear spoiler. Many owners remove the spoiler from their Mustang to streamline the look of the vehicle. If you wish to remove the spoiler from your Mustang GT, you can do so in less than 20 minutes, with common tools that you probably already have in your garage.
Open the trunk lid to allow easy access to the spoiler. This can be done using your Mustang's key, or by using the remote trunk release that is located inside the vehicle.
Remove the trim pieces or plastic plugs on the interior of the trunk lid. This will allow you to access the bolts that hold the spoiler onto the trunk lid.
Locate the bolts that hold your spoiler onto the trunk lid. Factory Mustang GT spoilers are usually held on by four bolts. If your car is equipped with an aftermarket spoiler, the bolt setup may be different.
Remove the bolts from the spoiler using a metric socket. It is helpful to remove the bolts on the left and right sides first, and the center bolts last. This allows you to hold onto the spoiler as you loosen the bolts, and avoid damaging your Mustang's paint or rear window.
Remove the spoiler from the top of your Mustang's trunk lid. You may wish to have a friend help you with this, to keep the spoiler from slipping and damaging your paint.
After you remove the spoiler, you will either need to install another spoiler, or use bonding compound to fill in the holes in the trunk lid. If you leave these holes exposed, water and debris can leak into your vehicle, and cause the trunk lid to rust.