I did mine yesterday. You hit the link on the UO page for accounts, then you edit account and it takes you to an EA website with War Hammer.
So, I tried to create an EA account but I already had one on that email, so, I requested the password and then if you read down underneath there, it tells you, you can use your email address. Then you put in your password.
So, I created the EA account and I had a persona name on it. This is really what the master account is that you can link the other accounts to. So, if you got this far, you're in the right spot but when you read across the tabs, it says Billing and there's a few other tabs. Well, there was a tab missing so I couldn't get any further.
I was using Fire Fox and switched to Internet Explorer just to see if I was missing something so I had to put my email, password, got into my persona account with EA and with Internet Explorer, there was another tab.
This is the most important tab, if you don't see it you can't do it. So, you click the link accounts and you should see a list of your accounts. Then there's an empty box where you put your password in.
So, all you need to know is your password for that account, just like if you were logging in. Then, if it takes the password it says successful, then you hit continue and it puts that account into the EA account. Now you use the drop down tab to change into any of the ones you were successful with. I have a couple that I forgot the passwords for.
So, then you can go into Billing and activate that account. So, it worked for me but if you don't see that link accounts tab and if you go in that link and there's no accounts listed, I don't know what to tell ya.
I was surprised that Internet Explorer beat out Fire Fox, in this case, for me.