How can I run git submodules?

I am trying to make use of Wikislurp to dynamically read Wikipedia articles.

The readme file states the following:

After you have clone the repository, you'll need to run the following to pull in all the submodules:

git submodule init
git submodule update
cd externals/curlcall
git submodule init
git submodule update

But how do I do this? I have no experience with git whatsoever and a search didn开发者_StackOverflow社区't give me anything usable.

Maybe you need to install Git for this...