Omg, I have been dying to do this for so long and finally worked it out today.
Basically, back when I started this blog I signed up using my old hotmail account. I never check it, and basically use it to sign up to things I’m testing out.
After getting into blogging and gmail, I noticed something that pissed me off EVERY TIME I BLOG!. That if I’m logged into my Gmail account, it tries to access blogger through that account, and not my hotmail (actual login).
Now there was much debate and confusion about why you can’t change the set email from one (hotmail) to gmail. Basically the gist of what I read was that blogger uses it as a username. Registering one user to a specific email.
HOW TO CHANGE IT:
1) Set up an account with your gmail. (call it Username 2), ie mine was Insanity540 2
2) Log into your old blogger username and invite that gmail account as an author.
3) open gmail, accept the invitation as an author.
4) go back to old blogger, make the new user (gmail, Username 2) have ADMIN rights!
5) log onto your gmail blogger account, check its all working, then delete the old author.