My hardtop doesn't rattle, so I've never needed to adjust it. But there are a few adjustments that can be made to the rear posts and the front attachment points can be shimmed.
Also, I once saw another thread where someone heard a rattle, and it turned out to be their folded soft-top was rattling in the storage compartment when stored, and not coming from the hardtop at all.
Anyway, for the hardtop adjustments, see this pdf I found. Sorry the pictures in it are a little fuzzy: