Rub his muzzle vigorously but lovingly. Give him major massages on the lips and chin. Hold his tongue and teach him to lead by the tongue. This takes a bit of feel, timing and balance. You have to be careful not to grab and pull the tongue if he tries to pull away.
Stallions are a whole other ball game.
I hesitate to give advice on how to handle a biting stallion because using the techniques without the right attitude, feel, timing, balance, savvy and experience could get you in a lot of trouble. Stallions are extremely dominant and full of energy and play. Their job is to be dominant and they don t take kindly to things getting in the way of their sexual responsibilities. All the solutions I ve suggested for biting horses relates just as much to stallions as to other horses, it s just that it takes more expertise and savvy on your part to be able to play games with a stallion. I strongly recommend that one becomes more skilled and savvy at the 7 Games with other horses before starting with stallions.