Step 2: After installing, you may need to install this script on your browser. If a restart requires, you may restart your browser for better results. Install this script to delete all friends.
Step 3: Now, navigate to the below URL and see a new option on your timeline to delete all friends.
[You must be registered and logged in to see this link.]
Step 4: Just scroll down to see all friends. After scrolling, just press Select All button which will be available at the top and hit Delete Selected Friends.
Step 5: Deleting may take few minutes if you have more friends but it will be more faster than you do manually. This will unfriend all your friends but you can also select friends specifically from the checking the check box.