I saw this video on how to clean up pet urine but its completely wrong. Vinegar and water is one of the worst things to put on a pet urine spot. The home cleaning expert in the the video says that vinegar is acidic and will kill the bacteria in the urine stain. Problem is that most bacteria can survive in a low pH environment. It's true that vinegar has some antibacterial properties but not enough to tackle urine spots.
Vinegar can actually help set a urine stain and can make it more difficult to remove. I tell all my Tampa FL customers that the best way clean up pet urine is to use a lot of water. Use about 3 times more water then there is urine. In most cases 3-4 cups of room temperature water. Pour it around the spot moving toward the center of the stain. Let it sit for about 30 seconds and then start to towel it up. Use more then one towel and get up as much as possible. If you have a wet dry vacuum you can use that to remove the urine and you will get about 90% of the urine out.
If the urine stain has dried it has most likely set into the carpet and will not easily come out. You can use the same procedure mentioned about but be prepared to do it at least 3-4 times before removing the majority of the urine.