deleting old service address

I moved 2 years ago and was given a new account number.   My old address and account number still show up under "My Account"   I tried to delete but when following the instructions and clicking on "account and identity" I get logged out.  I tried several times.   Reason I want to delete is that I cannot add my phone number for account recovery since it is associated with the old account.   Not sure if deleting the old account  will allow me to add the phone number or if there is another solution?