Password not accepted after user name change

Hi there. I'm fairly new to OSX and have just found the first thing that really annoys me.
I have just changed my account name. Then I started a rather lengthy rsync task and went away for a few minutes. When trying to unlock the screen, my password is not accepted. I noticed the account name is still the old one, so I assume I would have to reboot first, so the lock screen "knows" about the change?

That kind of sucks. I can monitor the rsync task via ssh, so I can just wait until it finishes and then reboot. I would however like to use my MacBook. So any ideas to how to get in? I do have ssh access as stated above.

 

Hi. Thanks for the answer. The link does not work however. Now it does. Nevermind.

Also, the problem is solved now. Rsync finished, I rebooted, password works.
I would just have preferred OSX wouldn't have locked me out in the first place, so if I did indeed do something wrong, I would appreciate a correction:

I simply went into System Preferences/Users & Groups, chose my User (Admin btw) clicked into the Full Name-Field, typed in my password to enable input, changed the name then closed the window.

Anything wrong with that?