Separating him from his hens is a tall order. Most will try calling to the hens to try and bring them in close with the gobbler in tow. When you hear the hen calling try to imitate what she is saying and give it right back to her. Try to get her aggrevated. With luck she'll come to see the intruder and put you in your place. Odds are not in your favor. It works sometimes. Usually the hen/hens pull him the other way.
My best advice to you is find out where they are heading and try him later in the day after the mourning breading routine. Better yet later in the season when he breeds all his hens and they aren't paying attention to him.Toms tend to stay with or close the hens throughout the day during this period.
Satellite toms hanging around the breeding group are your best option.
If later in the mourn/day you think he's away from his hens get as close as you can before calling. If he decides to come there will be less of a chance for one of the hens to come in and steal him away.
What you are trying to do here is a difficult task. Most hunters will leave this tom alone until he's vulnerable later in the season.