CAUTION: Do not overtighten the parking brake cable adjustment nut. Overtightening will cause the brakes to drag or lock up.
1. Remove the access cover inside the floor console bin.
2. Position the parking brake handle up at the fourth notch to access the adjuster nut.
3. NOTE: The rod is staked to prevent the removal of the nut.
Loosen, but do not remove, the parking brake cable adjuster nut.
4. Apply the tension by tightening the parking brake cable adjustment nut until there is no lash in the system with the handle in the lowered position.
5. Cycle the parking brake control 4 times and adjust as necessary.
6. Lower the parking brake handle and install the access cover.
7. Test the parking brake system for proper operation.
Source: Ford 2007 Mustang Workshop Manual 206-05-5.