Our live chat service is available for if you need assistance right away. We also offer a call back option that you can submit a request for from your DreamHost panel. Both live chat and phone support can be accessed by navigating to 'Support' > 'Contact Support'.
If you wish to transfer domains from one account to the other and divide them we have an article here that will give you step by step instructions:
The first steps would be to back up the sites content, and create another account. Once you have done this you can delete the domains that you want to put on the new account from the old one and start the domain transfer process. After the transfer process has completed you can re-upload the backups you made of your site to the new account.
If you have any additional questions please let me know.