Lots of patience and working with your horse on a daily basis. Start with your horse leading with a halter and walk and stop and teach your horse to stand after stopping. It will take lots of work and patience but in the reward will be great when you are showing your horse or just on the trail.
It isn't their nature, and you need to train him to your expectations. Slow, steady, patient, gentle in voice and manner, and always let him know where you are.