This is a pretty ingenious yet simple deal. First, you ream out the puncture with the provided rasp, then you stick the cone-shaped nozzle of the plugger tool into the hole. Load one pre-moistened mushroom plug into the tool, screw the tool into the nozzle and crank away on the end of the tool with the supplied Allen wrench, which shmooshes the plug through the nozzle and into the tire. Remove plugger tool, et voila, the mushroom is in there. Yank on it to make sure it's seated. Reinflate the tire using supplied CO2 cartridges, trim any excess plug material and away you go.