Just convince him you want him to go where you want to go, or settle on an alternative route. Can't make a donkey do what he really doesn't want to do and it isn't worth the fight. Our donkey is paired very strongly with one of our mares so he will do just about anything that she does, like trot happily right into the trailer after her, where alone he would plant his feet and need to be dragged over to a trailer. Just need patience and a sense of humor, life is too short to not have a sense of humor when handling a donkey.

"It's really quite amazing what a horse will do for you, if he only understands what you want. 
And it it's also quite amazing what a horse will do to you if he doesn't." ~ Bill Dorrance