How do I replace my garage door bottom seal on an uneven surface?

To replace a garage door bottom seal correctly, cover the floor strike piece (the aluminum or metal part in the ground) with a polyurethane seal material. Typically, this also has a built-in half instep frame for the lip from your garage floor to the strike below. Use epoxy to seal it in place. The second part involves another piece of polyurethane or rubber hosing that not only fits the center track of the garage door, but also has two lips that come up from the base of the door about half an inch. This also epoxies in place. Because the materials are polyurethane, they should take care of sealing uneven areas. If you have an uneven area, you may try to remove the strike piece and build up the area beneath, always checking with a level.