A tire plug kit is a small set of tools that you can purchase together to fill minor leaks in a tire. It includes a rubber plug, a reamer, and an applicator. The reamer is designed to make the hole round, and the applicator is a small metal pole with a loop at the end. Buy a tire plug kit online or at your local auto parts store. Hold the tire upright on the rubber and brace it with your nondominant hand. Then, force the pointy end of the reamer through the hole to enlarge it. Slide it in 13in (2.57.6cm) to smooth down the edges of the hole. This will create a hole with an equal amount of resistance on each side. Do not remove the reamer once you insert it. If you can't get the reamer into the hole because the tire is too deflated, fill the tire with your air compressor or pump before doing this. If you don't have a reamer, you can force the head of a nail or screwdriver through the opening of the hole and hold it in place. The applicator is a metal rod with an oval-shaped opening at one end. Take your rubber plug and pinch it at the end. Force the pinched end into the opening at the end of the applicator. Once the rubber is poking out of the other side, use a pair of pliers to grip the rubber and pull it all the way through. Continue pulling the rubber through the applicator until you reach the middle of the rubber plug. The applicator has a small 0.250.5in (0.641.27cm) gap at the end of the oval-shaped opening. The applicator is used to force the rubber plug into the opening before pulling the applicator out. If you don't have an applicator, simply grip the middle of the plug with a pair of thin pliers. With the reamer sticking in your tire, remove the valve cap on the air valve. Insert your compressor or pump and fill the tire with air. Continue filling the tire until the rubber is tight and the pressure is between 25-30 psi. Reattach the cap by turning it clockwise until it won't move any further to close it. Don't worry if a little air escapes while you're holding the reamer in place. It's okay if a little air gets out. Take a bottle of rubber cement and open the cap. Use the built-in brush or grab a clean 12in (2.55.1cm) natural paint brush. Dip the brush into the rubber cement and liberally coat each portion of the rubber plug with the rubber cement. If you want to keep your work surface clean, put a towel underneath the plug as you apply the cement to catch drips. Keep the tire still by bracing it against your body or setting it on its side. Then, pull the reamer out of the hole. As soon as you can, stick the applicator through the center of the hole. Push it in so that the rubber plug folds in half. Continue to push the plug into the tire until roughly half of the plug is sticking out the top of the tire. This can be kind of awkward to do without an extra set of hands. If you can, ask a friend or family member to hold the tire for you while you do this. Be prepared to use a little force to shove the plug through the hole. The rubber plug is bigger than the hole you made with the reamer, so this can be a little tough. Once the plug is roughly halfway in the tire, pull the applicator up to release the plug. The tension from the hole will hold the plug in place as it slides out of the thin opening at the end of your applicator. If you accidentally push too hard and shove the plug entirely into the tire, lift it out through the hole slowly to catch it in place and pinch the plug while you slide the applicator out. Tor remove the excess rubber, grab a pair of snips or wire cutters. Clip the rubber near the base of the tire to cut the excess length off. If your rubber is softer, feel free to use scissors instead. Give the rubber cement 12-24 hours to completely dry. When the cement is dry, refill the tire with air if necessary. You can pour tire sealant over the plug if you're worried about it sliding out. This shouldn't be necessary if the hole is adequately sealed. Reattach the wheel by placing it in the frame of the wheelbarrow and tightening the nuts.
++++++++++
One-sentence summary -- Get a tire plug kit with a reamer, applicator, and rubber plug. Insert the sharp end of the reamer into the hole to make it round. Thread the rubber plug through the opening on the applicator and pull it through. Use a compressor or air pump to fill the tire to 25-30 psi. Coat the rubber plug in rubber cement with a brush. Remove the reamer and force the applicator through the hole. Lift the applicator out to leave the rubber plug in the hole. Clip the excess rubber with a pair of snips or wire cutters.

7-Zip is a free utility that can quickly decompress TGZ files. It's a good idea to download a .exe file of the most recent version (that isn't a beta). Be sure to click the link next to the right version of Windows (32-bit or 64-bit). This opens the 7-Zip installer. 7-Zip will now install on your computer. Once the installation is complete, move to the next step. A menu will appear. An additional menu will expand. This tells 7-Zip to create a new folder (named after the .tgz file) in the current directory. The contents of the file will now extract to the selected location. If the only file that appears ends in .TAR, double-click it to extract the remaining files. To select a different location, choose Extract Files instead, then choose a location.
++++++++++
One-sentence summary --
Go to http://www.7-zip.org/download.html in a web browser. Click Download next to the correct version. Double-click the file you downloaded. Click Install. Right-click the .tgz file. Navigate to the 7-Zip menu. Click Extract to (Folder Name).