Easy answer: you don't. Cat pee is very different from dog, or even human, pee. It has very different proteins in it that are made to bond to surfaces, which is why cat urine gets sticky as it dries. I had a rug professionally cleaned after my cat peed on it and it seemed to remove the smell, but you can still smell it on humid days. And, cats can still smell where they've peed even if you can't smell it. Whatever you do, do not use anything with ammonia in it - it's baaad news when combined with cat urine, which is already extremely high in ammonia. If the urine penetrated the pad and floor, you have a bigger problem. Once the urine gets into the wood, there's no remedy other than ripping up that section of the floor.