Mayday/Green Flag

I have two cars overed un the breakdown scheme, my own and my wife's. She has recently changed cars and I wanted to take the old one off and put the new one on the breakdown cover.  Having missed their opening hours I tried registering on line but the instructions do not seem to fit as they refer to a policy schedule which I do not have an the membership number thta I do not have is rejected. Has anyone else manged to register and if so how?

 Thanks

Harry