(via [this page][1])

**To remove a submodule you need to:**

 1. Delete the relevant line from the `.gitmodules` file.
 2. Delete the relevant section from `.git/config`.
 3. Run `git rm --cached path_to_submodule` (no trailing slash).
 4. Commit and delete the now untracked submodule files. 


 [1]: http://git.or.cz/gitwiki/GitSubmoduleTutorial