Organize my accounts - Need help

I used to be on shared hosting many years ago. I would use my various cPanel accounts to host content for people or projects. Over time, I ended up with 3 different shared hosting cPanel accounts on various web hosts, each with a couple of domains under the main account.

I moved to a vPS and had everything transferred over for me which I now manage under WHM as a series of separate accounts. However, now I have 3 different accounts that have up to 5 domains each under them and what I really want to do is have 1 domain per account.

Part of the reason for me posting this is because I am not exactly sure how to move a domain under an account to an account of it's own. I am about to transfer all my accounts from my current VPS to a VPS at a new company and I want to get everything straightened out before I do that.

My question: Is that easy to do or is this going to be a nightmare? Most of the domains are wordpress blogs with a few of them being other combinations of content and application.

If you need any more info, let me know. I've included a very rough visualization of my accounts.

Thanks,
A

Edit: damn, the image didn't attach properly. If you need it, let me know