Trying to replace my old kitchen faucet. Under the sink there is a brass tube that runs between the handles to carry water to the faucet and the sprayer. It appears that I have to remove the faucet from the top, but not sure how to do that. It would seem if this were in fact the case, there would be some way to grip the base on top of the sink to unscrew it, but it is completely round and smooth. Hate to break it trying to "wrench" it out of there.