To remove a partition on a Mac computer, select the partition in Disk Utility, click the minus button, and click Apply. Deleting a partition also permanently removes any data on that partition, so be sure to back up everything you want to keep before doing so.Continue Reading
Double-click the main drive icon on your desktop. In the folder window, open the Applications folder. In Applications, open the Utilities folder. Finally, double-click Disk Utility in Utilities to open it.
In the list pane on the left-hand side of the Disk Utility window, click on the hard drive where the partition you want to delete is located. Notice that partitions may also be listed in the pane, but you must select the hard drive which contains the partition to be deleted rather than the partition from that list.
Click on the Partition tab. A table with a list of partitions in the hard drive appears under the Volume Scheme section.
Select the partition to delete from the partition table. Click on the minus button under the table to remove the selected partition. Note that changes are not committed until you click Apply. You can click Revert if you make any mistakes.
Once you are satisfied with the changes, click Apply. In the confirmation prompt, click Remove. The partition is now permanently deleted.