All friends can also be unfried by the activity log on Facebook profile.
1. First of all, go to your Facebook profile.
2. Click on the activity log.
3. Now, click on the more.

4. In this step, click on friends.

5. In the friends' option, you will see the added friend option. Click on Added friends to unfriend all Facebook friends.

7. You can easily remove the friends using the pencil icon. It will help you to remove all FB friends in a fast way.

Now, you can remove all FB friends without any tools and chrome extension.