If you have a change you would like to make across a large number of posts, the Bulk Actions > Edit option is going to save you a ton of time!
Bulk Edit Posts
► Login to WordPress if you aren’t already.
► Click on Posts > All Posts.
► Select the Posts you would like to edit by clicking in the box to the left of each post or by click on the box next to the word ‘Title’ to select them all.
► Click on Bulk Action > Edit.
► Click Apply.
This opens the Bulk Edit options.
You can change the Categories, Tags, Author, Comment options, Ping option, Status, Sticky options and Format.
► Make the edits you would like.
► Click Update.
Congratulations! You just did a bulk edit of your posts.