From the local repository folder, right click and select 'Git Commit Tool'.
There, select the files you want to upload, under 'Unstaged Changes' and click 'Stage Changed' button. (You can initially click on 'Rescan' button to check what files are modified and not uploaded yet.)
Write a Commit Message and click 'Commit' button.
Now right click in the folder again and select 'Git Bash'.
Type: git push origin master and enter your credentials. Done.