Repairing a tire properly requires it be demounted from the rim so it can be inspected on the outside and inside, remove damaged material, fill the void with rubber and seal the innerliner with a ...
Needle-nose pliers help get the plug into the plug insertion tool. You want to center the plug in the tool before inserting it into the tire. You can now pull out the object that has created the leak.
A flat mower tire doesn't always require a full replacement, and simple steps can get weekend yard work moving again long ...