- Create an empty Google Apps Script project at https://script.google.com/home
- Delete all content of the file Code.gs in the Google Apps Script editor
- Paste contents of script.js into Code.gs (SCRIPT WILL NOT RUN SUCCESSFULLY YET)
- Edit last parts of variable declaration on lines 6-9 to appropriate values
- Select "Run" at the menu bar at the top of the Google Apps Script editor
- The script will start running, and you can select "Execution log" in the menu bar to see a detailed status of what is happening
- Have fun, but make sure to get permission to spam someone before you do it
DISCLAIMER: This is for educational purposes only. Do not abuse.