What screws? I assume you're referring to bolts, but which ones? There are two under the dash that clamp the column down, and then four that connect the column to the steering box via the rubber disc-shaped coupler under the gas tank. Unless you're referring to the screws that hold down the horn ring, though I've never heard of them being difficult to remove. In any case, your options are the same. WD40 isn't going to do the trick, use PB Blaster. You should be able to find it at any auto parts or hardware store. If that doesn't do it, heat them up with a torch for about a minute and try again.

Dan