I would top it, to say half the height. Let that rot down, then top again to tidy up before the spring growth starts.
Or shove a load of sheep on it, but it might not have much nutritional value so you may have to supplement them. If you can get a big load of sheep from a local farmer that would probably be best, and I mean a big load, just for a few days. They will eat what is good and tread in the rest. Then you can top to tidy up before spring growth starts.