Send him a formal "invitation" in the form of a card or email (appropriately titled "be careful what you wish for") telling him to meet you at a certain time, wearing whatever you tell him to, and the exact position he should be in when you arrive to the "meeting".
Have the "no turning back now" conversation with him. Confront him, and makes him confess…. Tie him up or lock him in a cage while you run through this blog or some other list of all the crazy fetishes he has.
Show him pictures or recall specific events or specific proof of how you know he loves these naughty fetishes. Be understanding and promises him you won't tell anyone as long as he follows your instructions.
Then confidentially and firmly assume the role of the superior authority and begin to have s long and serious conversation with him about the changes you have in mind for him.
Make a list (you can use the 100's of ideas on this site) of things that might happen to him. Make him understand that these are not just threats, but that your WILL soon or later follow through with them. Make sure he completely understands that he's giving up control and changing the dynamic of your relationship. Make a list of new rules that he will immediately have to comply with, right them down, and read them off...obtaining his confirmation each time.
Tell him from the beginning what you will expect from him on each day of the week, every week, until you say otherwise. You need to be very prepared to have this conversation, so please make sure you do the proper research and prepare ahead of time. This conversation should be video recorded and kept to tease him with later. This will be the day you'll both always remember, when you took formally started training him and re-positioned the relationship. Therefore this conversation needs to be serious, sincere, kind, strict, firm, and fun....and most of all unidirectional, coming only from you!