please post pictures.

Almost all ways are better than 'whacking' it off at five feet. You're proud of it, don't ruin it.
Yes, please post a picture.
Mike

Pruning is never a "requirement" with Japanese maples but rather an aesthetic choice. I know of many, many JM's that have never seen pruners (or so seldom that they wouldn't recognize them!) and most look just fine and are structurally sound as well.

As previously stated, a photo of the tree in question is essential before anyone can give appropriate advice. And as an aside, "whacking" and Japanese maples should never be used together in the same sentence :-) Of any type of ornamental tree, the correct pruning of JM's is an art rather than a science and a very delicate hand should be used at all times. Once it's off, you can't put it back!!