Removal of pet urine stains from carpet is not always an easy task. The first tip to make it easier is to try to clean it while it is still new (still wet and right after it happens).
If the stain is still wet, soak up as much of it as you possibly can with paper towels and newspapers. If you wait too long, not only is the stain going to be more difficult to remove, but if your pet notices the smell at that spot, they are going to use the same spot again and that's the last thing you want to happen.
Blot the wetness with the newspaper and paper towel, do not "scrub" it. If possible, put newspapers underneath the wetness, too, so it can soak some up from the bottom.
As a side note, the Humane Society suggests putting the paper towels that you used to soak up urine near the litter box so the pet will be reminded where the proper place is for that activity.
After you have soaked up as much of the pet urine as you can, rinse the spot completely with cool water and then once again blot the wetness out of the carpet.
If you were not home or did not see the "accident" right away and a stain has already set in, there is a different way to clean it. If at all possible, rent or borrow an extractor vac for the best job at removal or if you have a "collection" of pet stains.
There are products that work on breaking down the urine proteins for easier removal and a pet store should be able to suggest which product will be best.
After you have cleaned the area thoroughly with cool water, use a pet odor neutralizer. Often when we think all traces are gone, the pet can still smell it and may decide to use the area again.
Ask your pet store or even vet for a recommendation for an enzymatic cleaning product.
If the pet urine has soaked through to carpet padding, you may want to consider replacing that portion of the padding.
Those are some things to do. What should you NOT do? First of all, do not use a carpet steam cleaner although it may be your first thought. The heat will set the stain and even the odor making it much more difficult or impossible to remove at some point.
Do not use cleaning products that have strong chemicals.
