Fixing a flat tire is pretty easy once you find the hole and have a tire plug kit.
To repair the tire you will need to:
Remove the object with a screw driver or pair of pliers.
Use the ream tool to make the hole the correct size for the plug.
Put the plug material on the insert tool, press it into the hole, twist 1/4 turn and pull the tool out.
Now your hole should be plugged.
Check for leaks and inflate to the proper pressure.
>>>This video will show you how to get this task done.