git: change origin of cloned submodule

This apparently is very much dependent on the version of git you are using.

1. If present, change the url entry in the [submodule "<dirname>"] section of the .gitmodules file.
2. If present, change the url entry in the [submodule "<dirname>"] section of the .git/config file.
3. Change the url in the configuration of the submodule itself. The location of the config file is version dependent. Older versions had it in <dirname>/.git/config, newer ones in .git/modules/<dirname>/config. However, you can always use below command:

cd <dirname>
git config remote.origin.url <new_url>

In other question I found answer for more modern Git version (2.25)

git submodule [--quiet] set-url [--] <path> <newurl>

Let's assume that you have submodule in directory external/foo-lib which origins is https://github.com/example-user/foo-lib.git and you want to change it to yours fork https://github.com/your-account/foo-lib.git then in root directory of git project type:

git submodule set-url external/foo-lib https://github.com/your-account/foo-lib.git