Multiple Accounts on CrackBerry : How to close?

Hi Forum Mods,

I just discovered that I have 2 accounts on CrackBerry. I had made an account a couple of years ago for my old BB 8520.
Later on, when I purchased the BB z10, I made an account (forgot that I already had an account).
Now I realize that I have 2 different accounts on the CB forum.
I would Like to close/cancel my older account [Username BD_BB_8520] and just keep the account I am currently using [ Username Y.Z.]
Please tell me how I may close the older account. Thanks in advance,

Y.Z.

email accounts at mobilenations dot com please...