multiple remotes

Problem: I'm working on a project that will eventually be open-source, but until I get it to a presentable state I want to store its code in a private repo on Bitbucket. So I've been happily building and committing, pushing to my remote on Bitbucket. Then I want to quickly test creating a public repo on GitHub and posting to it. So I create a new GitHub account, new SSH keys for it, and -- inevitably -- accidentally make GitHub my new remote origin. Now I'm still not ready to go live with this, I've deleted the GitHub repo but now need to set my local repo back up with the Bitbucket remote.

Solution: First, remove the GitHub remote: git remote rm origin. Now, add the older Bitbucket repo: git remote add origin [url]. But now, when I try to push to the remote branch with git push origin master, I get this error:

remote: Unauthorized fatal: Authentication failed for 'https://xxxxx@bitbucket.org/xxxxx/proj.git/'

Following this SO answer I removed the remote branch and re-added it using the SSH url. After this I was able to push to it.