Cancelling a Time Machine backup is a easy process that can be done with just a few clicks.
First, open Time Machine Preferences. You can do this by opening the System Preferences window and clicking on the Time Machine icon.
In the Time Machine Preferences window, click on the Select Disk button.
In the Select Disk window, select the disk you want to stop backing up and then click the Stop Backing Up button.
You will then be asked if …