Earlier, when you post something to Facebook, it was not editable, later Facebook changed it a bit so that you could edit your comments. What we were doing was either add an image so that we can edit the photo posts, or delete the post and repost it, the problem is that, it will loose all the comments and likes 
. Now Facebook allows you to edit your posts.
Now you can choose edit post from the menu and edit your post.
This change will be available for the web users and android users first. Android app for the Facebook will get this update soon and iOS users will have to wait.