As Anne says, there is no way to change names on a tapu, so in effect you and the two people you own with have to sell the property to the new two and the two you currently share it with. With that comes a new search, property purchase tax and all the other costs you paid first time around. Speak to Ozlen, it isn't as complicated as it sounds, but it won't be a couple of hundred quid either - although her fee will be dwarfed by the other costs.