Have to say this is a remarkably easy operation in GIT. Drop the files in the directory, open the GIT GUI and you’ll see it marked under unstaged changes.
Double click the file, and it will move to staged changes – that is, it will be committed to the repository when you commit.
Then click Commit.
Note: If the files are not listed, click Rescan.
Note 2: When you commit, you commit to your local repository – you then need to “push” to the remote repository.