Or you may accidently add someone you don't know and you want to unfriend or remove him .
This guide will show you how to delete friends ( Unfriend ) on Facebook in a very easy way :
1- Go to your friend's profile (timeline)
to go to person's profile just type his name in the search box or click on his name in any of his posts .
2- Hover over the Friends button at the top of his profile (timeline) and click Unfriend
3- you will see a confirmation dialog, Click on ( Remove from Friends ) to Delete this person from friends .