You will need to remove everything you can that has been marked, but this worked really well on a hard wood floor, it was a last chance before we ripped it out and it saved me a LOT of work.It is an enzyme cleaner so something else like it might work as well.I bought it at Home Depot.

All of the enzyme products I've found are specific to either dog or cat, I can't find a single one for humans. 

You have to hit it with an enzyme product like, I think it's called Pee Be Gone...or something like that.  

Just google eviction service near me.It is pretty normal for the new owner to deal with that; the only way I have been able to get around it is by making the EMD non-refundable, which gives the seller confidence you will close or at least let them keep the EMD for damages.In terms of the pet smell, order a 40yard dumpster and get everything out, next any good PM can hook you up with an enzyme spray treatment that will metabolize the pet urin.

I think she would magically become more helpful after that.Also look into enzyme products then possible muriatic acid then kilz sealer

Try enzyme neutralizer, ozone treatment and more serious solutions

@Lauren Gomez enzyme urine eliminator.

I used an enzyme cleaner on the base floor/subfloor as an additional step for pet odors but this one was smoke only and probably wouldn't help.

Use bio enzyme stuff for septic tanks ?

with the seller's full written permission, I patched the drywall, painted that room & treated the floor with enzymes to remove the stink.