In my past experience, lithium grease or automotive wheel bearing grease has worked fine. You want to put the bare minimum on there anyway, so we're talking tiny amounts. Then carefully wipe off all residue after focusing the lens a few times. The wheel bearing grease will definitely stay in one place and not migrate. It's designed to stay in one place in extreme temperatures. If this were a modern AF lens you'd want a thinner lube.
That's a great illustration of the take-apart process mdarnton gave. If you mark the place where the lens unscrews w/ a tiny mark on both pieces you won't have any problem reassembling the lens. Or, simply take a digital photo of the way it looks when the threads end and the lens is free, then restart it in the same place. Very easy. Also, it's very easy to restart the lens in the wrong place if you don't know what's up, but now you know. It's only one part. Look, the worst that could happen is you'll have to fool around w/ the lens a bit if you restart it in the wrong place.