Git

git submodule add git@bitbucket.org:pkgdata/<repo>.git chemin/vers/destination

git submodule update --init --remote <sous-module>

Delete the relevant section from the .gitmodules file.
Stage the .gitmodules changes git add .gitmodules
Delete the relevant section from .git/config.
Run git rm --cached path_to_submodule (no trailing slash).
Run rm -rf .git/modules/path_to_submodule (no trailing slash).
Commit git commit -m "Removed submodule "
Delete the now untracked submodule files rm -rf path_to_submodule

git reset --hard <commit_id>