1. First, navigate to the website that you want to use as your homepage.
2. Then in Safari, click on Safari / Preferences...
3. Click the Set to Current Page button
4. Close out of the Preferences window.

Windows:

1. Click on the Cog button
2. Click on Preferences....
3. Click on Privacy.
4. Click on the Remove All Website Data... button.
5. Click on the Remove Now button.

Mac:

1. Click on "Safari" up on the menu bar.
2. Click on "Preferences...".
3. Click on "Security".
4. Click on the "Show Cookies" button.
5. Click on the "Remove All" button.
6. Click on the "Done" button.
7. Close out of the "Preferences" window.