1) First get a nail in your tire and a tire repair kit. I purchased the Victor Deluxe Tire Repair Toolbox
2) Use needle-nose pliers. I could not find mine so I used another type.
3) Use the t-handle rasp tool (the tool that looks like a round file). Jam the tool into the nail hole.
4) Use the t-handle insert tool. Then try to insert the plug in the insert hole.
5) Then jam the insert tool with the plug into the nail hole 2/3 the way in. Then pull the tool out. (Do not leave the t-handle in the tire.)
6) Cut the plug.
7) Then pump up the tire to the correct pressure. Also use a good tire gauge and throw the gauge that comes with the kit away. Done.
This is the first time I have repaired my own tire so the steps may be incorrect. If the steps are wrong do not follow them. But they worked fine for me.