How to Mass Delete Your Facebook Friends
Whether you've had a falling out with a few Facebook friends or you're simply looking to pare down your friends list, entering each friend's profile separately in order to remove them from your list can be cumbersome. Because there is no way to delete your friends en masse, you can use the "Edit Friends" tool to quickly run through your entire list of friends and delete those you want to remove faster than deleting friends through their profiles. It'll save you time when you're removing a large amount of friends.
Sign into your Facebook account. Click the link that reads "Friends," found underneath your profile picture on your homepage.
Click "Edit Friends" at the top of the Friends interface. This will open a page of all of your friends in list form.
Sort the list by selecting the drop down menu on the left side of the page. Ensure that your friends are filtered by "All Friends." This will cause all of your approved friends to appear on the list.
Click the "X" on the right-side of a friend you'd like to delete. When the pop-up window asks if you're sure you'd like to delete that friend, select "Remove" if you're sure.
Repeat the process for any other friends that you'd like to remove from your friends list.