well as for best time? when the tree is dormant normally

I would cut back your tree when it is in an active growing period so that it has all of its energy to focus on back budding and producing new branches from the old leaf nodes. Sometimes you get a few branches, some get only one. That's why I have better results when it's actively growing.

Cut at (an angle 45degree) to where you feel it would be best and then seal the branch. Keep the new wound from moisture until it has hardened off naturally, or after you seal it with Elmers Wood ( waterproof) glue or another sealant . You should see new leaf activity in about three weeks or less.

Good Luck!!

Laura

Thanks for great advice. I'll give it a go.