Press lightly against your brake pedal to determine the amount of free play it has. Free play is the distance you can depress the pedal before you encounter resistance. Ideally, you should have about 10mm of free play in your pedal. Measure your actual free play with a ruler.
Find the brake booster adjustment rod. This is a small rod connected to the back of the brake pedal lever, at the rear. There are two adjustable nuts at either end of the booster rod.
Make a mark on the booster rod where you can see it, with either white-out or nail polish. This will help you gauge whether you're increasing or decreasing the height, once you start adjusting the booster rod. If the mark disappears, it means you're lowering the pedal.
Use your crescent-wrench to loosen the lower nut on the booster rod. While Ford typically employs specialty tools, this is one of the lucky instances where you can use a standard wrench. Be sure not to loosen the top nut, only the bottom.
Twist the booster rod with a pair of pliers. Turning it clockwise, toward the clutch pedal will raise the brake pedal and decrease the amount of free play. Going counter-clockwise will lower the brake pedal and increase the amount of free play.
Tighten the lower lock nut.
Test your adjustment by taking your car for a short drive. The pedal should be responsive and you shouldn't notice any unusual sounds. Also make sure your brake lights are working correctly.