If you have actually blocked somebody unintentionally or changed your mind about the block, though, it is also reversible. You can alter your Privacy settings to unclog and enable somebody back into your Facebook world.
How Do I Unblock People On Facebook
1. Click the down arrow beside "Account" at the top right of any page on Facebook.
2. Click "Privacy Preferences" from the Account menu.
3. Click the "Edit Your Lists" link under the Block Lists heading. It is at the bottom center of the page.
4. Click the "Unblock" link beside the name of the person you wish to unclog. A list of the people you have actually blocked is discovered under the Block Users area.
Idea
Unblocking somebody does not immediately put that person back in your good friend list. You should add the freshly unblocked person as a pal and wait on them to validate the request.
And one more thing please don’t forget to share this awesome trick to use the How Do I Unblock People On Facebook with your friends.