Originally Posted by urodacus

and another tip:

if you work with the bike clamped upside down, you can avoid those nasty filings getting into the BB without having to remove it. or you can plug the tube with a rag with a string attached above it, and hope to pull it up without dropping metals scraps down the tube. (maybe turn the bike upside down as you pull the tube rag out).

and grease both the tube and the post when you reassemble... I know Sheldon doesn't / didn't bother, saying it was like putting peanut butter on both pieces of the sandwich, but the top edge of the seat tube scrapes much of the grease away as you slide it in, leaving the very bottom of the seat post fairly unprotected if you only grease the post.