All I had to do were:
I did have one minor glitch when changing my default email address, but all it took to get it fixed was one brief call to Microsoft. The tech was helpful and efficient, knew what he was doing, didn't ask me a bunch of dumb questions, and got the issue fixed.
My next step was to look at the Office Admin center. Yay! No more missing or crippled functions!
Easy peasy! I highly recommend it! Of course, if you have a lot of users and/or a lot of stuff on SharePoint, you'll need more help, which Microsoft can provide locally depending on where you are, for a reasonable price.
I take it you still are issue free? I might have to look at doing this as I only recently bought my domain name but from the sounds of it foolishly signed up to go daddy email essentials to get a domain name email address. Now I can't install a paid office 365 product using my domain email address because it is already registered, yeah I know to me, apparently not. I am expecting a call from GD tomorrow as they are now refunding my email essentials but want to add website builder and hosting which is going to cost me an additional £72. I am now thinking I have really wasted money I can't afford and would have been better spent using the free ads and local paper to advertise on.