first of all kennel him...then he can chew his back wheels off.
if you want to stock brake him...walk him on a lead through a sheep pen..........when he starts to get excited..give him a good clout..........keep repeating this until, until he shows no interest...could take a while, but he should be young enough to learn.
sound like hes got bags of drive.....could be chewing out of bordum, of because he's wired up, fustrated and wants to be on.
What do you intend doing with him???????