How to remove an ex partner's name off mortgage deeds?

Well, you need to contact a real estate lawyer for this. When you bought the house you must used one, so contact the same one and let him know what do you need to do. It's not difficult as long as your partner is willing to sign. Apparently, there is something called "quit claim deed" which used to remove one's name from the deed. But your partner will have to do this, not you.