I've recently fixed a broken installation by reinstalling Ubuntu with a new username, and thankfully my old account survived (yay). Now I'd like to add my old account back to Ubuntu. Note that I'm not necessarily trying to overwrite the new user account. I just want to restore the old account and have it be the default when I boot up Ubuntu.
Edit I can create a new account under the old name but I'm worried that that will destroy the old account data.
Update
I've replaced the my new home folder with my old home folder but that didn't work.