Pretty much what everyone else has said.

As little as he is you could pony him off your horse and teach him that way..

So long as the donkey/mule isnt explosive you can get into a tug of war with them but it takes quite a bit of time to win , they are one of the most patient animals you'll ever meet.

"Blessed are the flexible for they shall not get bent out of shape"
"You can discipline and Discourage or you can Discipline and Encourage"
"Gentle in what you do , But firm in how you do it"