Buy yourself a thin rope training halter which works on the nose and poll
Buy a lunge line something about 20 ft long and a lunge whip
Buy yourself a tough pair of boots, so when the horse treads on your foot , he doesn't break your toes.
Buy a pair of good tough gloves
And start to work the horse in a closed pen in hand.
Each day,when you collect him ( if you can) then groom him - all over , even if he is not dirty. You are grooming him, for him to get to know you, your smell and your voice.
Fit the halter, attach a short length lead rope and lead him into the pen.
Lots of circles. Walk , stop, walk, turn about, turn right turn left.
Use 'Woah', 'Stand', 'Walk on'. Do some stands, where he doesn;t move for a few minutes. 20 minutes at least.
At first you may have to tug - but tug and let go. Tug and let go
Do this little routine every day, at the same time of day if possible.
Each day take two small apples chopped into 6 slices in your pocket - they are rewards for doing well. Maybe even presents because you are beginning to like him.
When the horse walks at your shoulder -on the right and the left - on a loose lead line then you are winning.
Then move up to lunging him. It is not difficult but ideally find a nice, gentle,
kind, sweet voiced, female who has experience with horses to show you how.
(You never know!)
The horse doesn't forgive you for neglecting him, so you've got to make good.
When you feel comfortable with him, then think of rebacking him - very gently.
Don't be in a hurry to get on his back until you think he trusts you. And when you do try have someone who is not frightened of horses with you.
You never know you might get to like it.