Force him to have high heel practice at least twice per week, for a minimum of 3 hours on each occasion. Buy locking high heels for him with an ankle strap where you can attach a lock using a key, so he can't take them off. Surprise him with a new set of high heels when he least expects it. Make him practice walking in the high heels in front of you (over and over again). Like a girl practicing her posture, make him walk back and forth with books on his head until he's had enough practice. Choose the same 2 days a week that you make him wear a bra to wear his high heeled shoes. Like wearing a bra, you should make it his initiative to put them on and keep them on at least twice a week for a few hours, and punish him if he doesn't comply by making him wear them longer or simply making him wear them in more public environments.
So he loves it when you wear high heels, and doesn't understand the complications and pain that involves. Make him suffer through it himself so he can develop a deep appreciation for those who spend all day long in high heels. He should be both stimulated by the opportunity to wear some wonderfully feminine shoes, while at the same time being reminded that you intend to take his fetishes to the extreme, much farther than he hoped or wanted.
You should ask him to do things that require him to be standing or walking often while he has them on. Ask him often how his feat feel, and tell him that you are beginning to like to see him in heals. Ask him to help you pick out his next pair of high heels. Tell him you are monitoring his progress in the heals and take a short 30 second video of him walking in them once a week so you can compare his progress.
Wear the keys to his locks on an ankle bracelet or on your necklace, clearly visible for him or anyone else to see.
Make it a strictly enforced rule, at least twice a week, for at least 3 hours on each occasion
you can do this alone or when you have female guests over as well. You should enforce the high heels being worn every time he's working with your cleaning lady.
You need to start with a reasonable heal size (not too big) and then gradually buy higher heals over time. You also need to make it clearly visible that you are enforcing this. Make a point of looking at your watch and marking the time when he puts them on, and make sure that he knows there's a minimum amount of time he'll have to keep them on. Assimilate that it is quite normal for you.