Step 1: Simply put your SD card into the SD slot and let the computer read it.Steps Involved in Accessing Files from Your SD Card Using a Mac With that said, how should you go about opening your SD card? All modern Macintosh computers, from your iMacs to your MacBooks and everything in between and beyond, make use of the SD slot to allow access to SD media. The SD (Secure Digital) memory card is a stable or non-volatile memory card or storage system known to last a long time like a standard HDD but has the portable accessibility of the more volatile flash drive.