help....

Ok so here goes hope I make sense.

So im just a Mum and have never used xbox live or even a console!

My son got an xbox years ago for his birthday aged about 13 and he loved it. He played for hours and set up a gamertag and eventually wanted xbox live to play Fifa with his friends. So I agreed eventually and set it up for him, It was billed via my debit
card as he didn't have one obviously!

Fast forward a few years and he hits 18 and agrees to pay his own live account but didn't want to change his gamer tag as he had downloaded games onto it. We transferred payment over to him and he pays for anything he uses. (He's at Uni!)

So the problem is that now my youngest daughter wants to have xbox live and we are stuck in a situation where I have nothing to do with my sons payments etc (although I do get an email every time he buys something) and want to set one up for my daughter
but am concerned it will transfer payments all back over to me. Im more than happy to transfer the entire original account over to my son as he is the only one using it but I don't know how!

Is this possible?? sign over the account to him and set up a brand new one for here??

:)