this is how i did it with basic Git commands:

git checkout hotfixes
git reset --hard master
git push --force origin hotfixes

of course it's important to notify everyone working on hotfixes. most likely they will have to delete their local copy and start from a fresh one. an alternative, less invasive idea is to create a new branch:

git checkout master
git branch -tb hotfixes-2 # this creates branch `hotfixes-2` from a copy of `master`
git push origin HEAD # this creates `hotfixes-2` on the remote server

HEAD is where your workspace is currently in the tree of git commits; detached means that it doesn't correspond to a branch. To fix this, you should create a new branch with git checkout -b branch (replacing branch with the name you want to give your new branch).

If you want to drop the commits following the one you reset to, you can delete the master branch and re-create it:

git branch -D master
git checkout -b master

If you're working on a repository which is pushed elsewhere you'll need to do more work to fix things up, possibly forcing a push (and telling every one else to re-clone their workspace). If you have shared state, you should really create a revert commit; take a look at git revert (starting from master and reverting all the commits starting with the one following c70e611).

If you have done it only locally you can switch to branch master, delete your local feature branch and checkout the remote branch gain:

git checkout master
git branch -d featurebranch
git fetch
git checkout -b featurebranch origin/featurebranch