Make sure you have all the important branches and tags on your local repo, delete the github repo, recreate the repository through usual means (no forking) and push the local repository back with git push --all
. Note that if you have local branches that you don't want to publish, might be worth to create a temporary clean local clone for the operation.
However, this will also get rid of wiki and issues. As the wiki is in fact it's own repository, it can be handled similarly by cloning it and then recreating and pushing. The repo address is on wiki's Git Access page ([email protected]:user/repo.wiki.git
).
This leaves issues. They can be exported through the API, but as far as I know, you can only create issues and comments with your person, so importing them perfectly is impossible.
So, if you need issues to be preserved, you should go through github support as Thomas Moulard suggests.