Delete a file from your Time Machine backup disk
You can delete all copies of a backed-up file or folder from your Time Machine backup disk.
Note: These instructions apply only to backups stored on an external backup disk. You can’t delete items from local snapshots stored on your internal drive.
Click the Time Machine icon in the menu bar, then choose Enter Time Machine.
If the Time Machine icon isn’t in the menu bar, choose Apple menu > System Preferences, click Time Machine, then select “Show Time Machine in menu bar.”
Use the arrows and the timeline on the right side of your screen to browse the backups Time Machine created.
Select the item you want to delete, then click the Action pop-up menu and choose Delete All Backups of [item name].
You can use the Finder to move, copy, or delete the Backups.backupdb folder on your Time Machine backup disk as you would other folders. You can delete folders within the Backups.backupdb folder, but you can’t delete individual items inside the dated folders.
Important: Don’t use Terminal or any other app other than the Finder to move, copy or remove items from the Backups.backupdb folder. Also, never modify or delete any items in the /. MobileBackups directory. Time Machine uses this directory to maintain local snapshots, which are deleted automatically by Time Machine when more space is required.