Hi Sup,

I am by no means a trainer, but when my horse got stubborn and didn't want to move forward I would put the lunge lead around his rump and put the pressure on as I was pulling on the halter. Music has had a professional trainer, but that was when he was three, three years ago. Since then he has been pastured with the mares without a job and so he would get stubborn every now and then. It worked with him, hopefully it will work with your horse.

I have also seen trainers use other horses in tandum.

Good Luck!