You spray a mixture of water and vinegar on it, but it does not completely take away the scent.
The best way to remove cats urine from carpets etc, is biological washing powder diluted with water. If you leave any mark that the cat has urinated in that spot and the scent has faded then the cat will more than likely urinate there again to remark its territory, so it is important to remove the scent straight away.
BioKleen makes a great product called Bac-Out. Soak the urine spot with the Bac-Out, wait approx. 20 to 30 minutes and blot it up. The smell will be gone, but the Bac-Out leaves a clean lime scent. It is a fantastic product and has worked for me when everything else I tried did not work. You can probably find at your local green grocery store.