Removing a submodule

You can remove a submodule (e.g. the_submodule) by calling:

$ git submodule deinit the_submodule
$ git rm the_submodule

• git submodule deinit the_submodule deletes the_submodules’ entry from .git/config. This excludes the_submodule from git submodule update, git submodule sync and git submodule foreach calls and deletes its local content (source). Also, this will not be shown as change in your parent repository. git submodule init and git submodule update will restore the submodule, again without commitable changes in your parent repository.
• git rm the_submodule will remove the submodule from the work tree. The files will be gone as well as the submodules’ entry in the .gitmodules file (source). If only git rm the_submodule (without prior git submodule deinit the_submodule is run, however, the submodules’ entry in your .git/config file will remain.

Taken from here:

1. Delete the relevant section from the .gitmodules file.
2. Stage the .gitmodules changes git add .gitmodules
3. Delete the relevant section from .git/config.
4. Run git rm --cached path_to_submodule (no trailing slash).
5. Run rm -rf .git/modules/path_to_submodule
6. Commit git commit -m "Removed submodule <name>"
7. Delete the now untracked submodule files
8. rm -rf path_to_submodule