If you require a completely new account, just create another one from the main DH page.
Be aware that if you use a promocode then the new account won't be able to host any domains that were hosted on current/previous DH accounts. If you signup without a referrer or promocode then Support will transfer domains from account to account.
This is just what I've learned since being here and is not an official post by any means, so of course contact DH via your panel and make sure they understand your intentions before proceeding.
Maximum Cash Discount on any plan with MAXCASH