Starring is fun!
Make sure that you are signed in your GitHub account, if not do so now!
Open star.user.js at this link here and copy the entire script.
To open developer tools on Chrome/Chromium please press ctrl+shift+I
To open developer tools please press ⌘+⌥+I
Click on the Console
tab in the developer tools to open it, then click on the text area in the Console tab.
Paste the script by pressing ctrl+V if you are on Windows or ⌘+V if are on macOS
Then press return / Enter