How to patch a tire
1.   Use your air die grinder to clean out the hole. Select a pointy bit that will fit into the hole where the leak is. This will roughen up the sides and clean the area so that the patch will bond correctly when installed.

2.   Change the bit on the die grinder to a grinding stone bit. Spray a "Pre-Buff Cleaner" on the inside of the tire where the patch will be installed. Use the grinding stone to clean and roughen up the area around the hole (about two inches in diameter around the hole). This will give the patch a clean surface to make bond with the tire.

3.   Spray compressed air to the area. This will remove any dirt or debris created by the buffing process. It is important to have a clean surface for the patch to bond to.

4.   Apply vulcanizing cement to the buffed inner surface of the tire. This will prevent water from entering the hole and moving its way into the tire’s tread. Let stand until the cement is "tacky" to touch.

5.   Remove the plastic that is on the sticky side of the tire patch. This is the side that will contact the inside of your tire.

6.   Push the pointy part of the patch through the hole. The pointy part should enter the hole from the inside of the tire and be pushed out through the outside. Use a pair of pliers to grip the pointy side of the patch. Pull this pointy part of the patch out from the tire's tread. This pulls the sticky part of the patch tightly to the inner side of the tire.

7.   Use a roller on the inner side of the tire patch. This will remove any air bubbles in between the sticky side of the patch and the buffed surface. The patch is now sealed properly onto the tire.

8.   Use rubber patch sealant on the inner side of the tire. You should cover the whole patch and some of the tire. This makes sure that there will be absolutely no leaks!

9.   Let it dry. It should only take a couple of minutes. While you are waiting, use a pair of side cutters (or scissors) and cut the stem of the patch to be flush with the top of your tread.