Not as easy as it seems, it is known as ISP migration Not all ISPs support it, and AOL may well be one of them
All Broadband connections are assigned a unique reference number so that BT can identify a customer regardless of which provider they are with. This reference is called the CBUK number. It always begins with the letters CBUK followed by eight digits eg"CBUK87654321". Most ISPs will give you this number on request, oyhers are notoriously difficult
Once you have got that code, you can apply to your new ISP, who can use this code to get you up and running on B/B
Please post your query to the boards as many hands make light work, and I'm not talking electricians! If your problem is solved, let us know so that others can learn.