Cut off the damaged leader if it remains attached to the tree. Use the saw or branch trimmers and cut off any other dead branches at the top, as well. Wearing work gloves, hold onto the branches as you are cutting them. Cut just below the dead part of the branches. If you are using a ladder, make sure the ladder isn't resting against the part of the tree you will be cutting off.
Choose a strong, healthy branch near the top of the tree to be the new leader. Tie the end of your string near the end of the branch using a double knot as you would when tying shoes.
Let the string drop to the ground, and make sure its length is at least twice the height of the new leader before cutting it.
Tie the other end of the string to the wooden stake using the same type of knot as before. The stake should be at least 2 inches thick and 2 feet long.
Pull the string tight so that the branch becomes as close to upright as possible. The tree should only be leaning slightly toward you.
Keeping the string tight, pound the wooden stake into the ground to keep the branch in the upright position.