You can delete specific local backups from the Terminal. Launch the Terminal (from Applications > Utilities), and then copy and paste this command and press Return:
tmutil listlocalsnapshots /
The Terminal will show a list of local snapshots with names like com.apple.TimeMachine.2018-03-01-002010
. To remove a snapshot:
- Copy and paste this command:Â
sudo tmutil deletelocalsnapshots
- Type a space and then paste in the date portion of the snapshot.
- Press Return, and finally press Return.
Altogether, using the example snapshot above, that looks like:
sudo tmutil deletelocalsnapshots 2018-03-01-002010
If it deletes properly, you’ll see Delete local snapshot '2018-03-01-002010'
 in the Terminal as the response.