You are going to have to stick it out there and make up a time estimate.... I'd plan on a day and a half with dumping.
To make things a little easier, shave off the front with clippers to get a better view of what to cut, then dig in with a chain saw and lops. Try to make as few parts as possible to drag to the trailer.
If the disposal will be a headache ( and there will be a lot to dispose of) look into a chipper for a day.... chip the debris and shoot it back under the hedge.