I have a git-project with a submodule. The new major-version of the submodule is located in a completely different repo on github. So, it has a new repo-url, which means that i have to update my submodule-setup.

I really hate git's submodule-handling so i sumbled upon various less meaningful error-messages on my way. The final answer looks quite easy:

git rm -rf [submodule_dir]
git submodule add --name new_[submodule_name] [new_submodule_url] [submodule_dir]

And it works well, if you go this way – but never take a look to the left or right!