Repairing a sunroof is a task that may or may not work, so it may be best to replace it, if it is broken. Choose the model sunroof you want to fix. Determine what is wrong with your broken sunroof by using a 4 mm hex socket to crank the sunroof open as you find the areas in need of repair. You can open the sunroof manually with the assembly on or off. Check with your dealer on manuals on how it fix a power sunroof yourself.