I would like to refinish or replace my laminate vanity top. I've read about a product called Klenk's. Will this work? If I end up replacing the vanity top, will it be a big job? I presume the new vanity top and sink will be a one-piece unit.

If you replace the original counter with one with a built in bowl you will most likely have to redo the trap assembly as they almost never line up. Good luck, Tom

All I can say is that if you try to refinish the existing laminate, you must sand off every last bit of gloss on it to get anything else to stick to it.

Careful use of a torch might let you remove the laminate like removing floor tile. Clean up the surface and add new laminate.