cd $HOME/Code/repo-directory
# Rename Origin to bitbucket
git remote rename origin bitbucket
# Add the origin of your new github repository
git remote add origin https://github.com/<username>/<repo-name>.git
# Push ypur branch master to your github repo
git push origin master
# Remove the old origin
git remote rm bitbucket
$ git clone https://github.com/cakephp/cakephp
$ cd cakephp
$ git push git@bitbucket.org:mg/cakephp.git master