If you are referring to a plug kit they are pretty simple. They are designed to be used on holes in the tread only, so if you have a sidewall rip you are OOL. You first locate and remove the cause of the hole (nail, etc.) On my kit you thread the plug through the applicator like threading a needle. You then coat the plug with adhesive and push it into the hole. The applicator is designed to put the plug in but not pull it out; the tip will come out leaving the goop-soaked plug in the hole. It's kind of hard to describe but very simple to use.