I've created a new orphan branch with git checkout --orphan orphan-branch and made a lot of commits on that branch.
Now I want to replace the master branch with the newly created orphan-branch, all the files and the history of the master branch should be replaced by the files and the history of the orphan branch.
What is the best way to do this?
To replace the history and old file of the master branch you need to do a forced update on it.
git push origin +your_orphan_branch_name:master
Attention: This deletes the whole history on the remote repository for your branch master. But that what you intended to do...