I think the best options are using a big machine if you can access one as others have said or build a router box sled deal and do it that way. The possibilities of screwing up the piece are endless with hand tools unless you are skilled at using them. From my experience trying to do a table top with a belt sander, you fix one dip, then create another, etc.etc.
Once you get it flat you can sand it with an orbital sander.....hard to mess it up too bad with one of those.
Last edited by RJY66; 04/05/20.
