I am in zone 4 and have a string of about 10 privets running the lot line.
Previous owners let these grow wildly out of control - I doubt that these
were ever pruned or trimmed. They are roughly 15ft tall and wide but
orignally had only a spattering of foilage. Each year, I've gone in and
mainly concentrated on trimming out dead and damaged limbs and cutting out
the other things growing in the middle of the privets (ie, little maple
trees, weeds, etc) - this takes forever because it is a tangled mess of a
decade or more without being maintained. However, the privets now have an
abundance of foilage.

They seem much healthier now and I would like to go in and get their size
under control and this will also help me get in and continue to prune away
dead limbs and other things that I just can't weave my way to reach right
now. What's the best way to get these trimmed down to size? I'd like to take
them from 15 ft tall and wide to around 6-8 ft tall and wide then I plan to
keep them pruned and trimmed to that size. Many of the branches are too
large for most hedge trimmers, so do I just take a chain saw and swipe up,
down and across to take 7 ft off the bush?