Plug your memory card reader
into a USB port on your Mac.
Insert the SD card into the
memory card reader's SD slot,
and the SD card will mount on
your Mac desktop.
In an open Finder window,
single-click "Applications" in the
Side-Bar and scroll down to find the
Utilities folder. Find Disk Utility in the
Utilities folder and double-click the
"Disk Utility" application to launch it.
In the opened Disk Utility application,
single-click to select the SD card in the
left-hand Drives column. Then, single-
click to select the "Erase" button in
the top row of radio buttons. Select
the format you wish to use to format
the SD card on the "Volume Format"
pop-up button. Use Mac OS Extended
(Journaled) for use on Macs and MS-
DOS (FAT) to share the SD card with
both Macs and PCs or digital cameras.
When you have finished selecting the
formatting options, click "Erase."
A new dialogue box will pop up in
"Disk Utility," asking if you are sure
you wish to erase the SD card.
Caution: Erasing the SD card will
permanently erase any files. Make
sure you have backed up any file you
wish to keep. To continue with the
formatting process, click "Erase."
Once the SD card has been erased, it
will mount on your Mac desktop just
as any other removable drive.