
You may need to take up the lino and treat whatever flooring is underneath... if any urine has leaked under the lino and gone into wood or other porous flooring then that will be holding the smell. Just as bad would be a non-porous subfloor (eg tiles, concrete) which might reveal a sticky residue where urine has leaked through or behind the lino and can't soak into anything.
Depending on the severity of the stink - spayed/neutered cats urinating inappropriately? A few occasions or weeks or months? Entire tom cats? - you might be able to clean the floor base under the lino, but you might need to sand and revarnish or paint soaked floorboards or other porous surfaces, to banish a very stinky long term habit. Cat pee does linger.
If it's not a giant issue then scrubbing the sub-flooring with biological washing powder might do the trick, plus replacing the lino. (When the lino is up you will probably see the main areas of staining and can treat accordingly).
Otherwise it will need some kind of re-sealing and new lino.