Cannot checkout branch or remove problematic files

I have 2 branches in my Java project: master and refactor. I've finished working on refactor so now would like to checkout master and merge refactor into master. While working on the refactor, I also added some files to .gitignore (one of them was .idea) and now I get:

[michal@michal-pc MCleaner]$ git checkout master
error: The following untracked working tree files would be overwritten by checkout:
Please move or remove them before you switch branches.

I've read many posts and nothing works. How can I remove those files without accessing master branch? Is there a way to fix that? Please provide cmd commands if you can, I'm still new to git.

Here is the output from git status:

On branch refactor
Your branch is up-to-date with 'origin/refactor'.

Untracked files: (use "git add <file>..." to include in what will be committed)

nothing added to commit but untracked files present (use "git add" to track)


  • Add the following to .gitignore


    and remove this directory

    git rm -r .idea

    Then commit changes.