Open a terminal window
Get a list of attached disks
Identify the SD card disk ID (not the partition).
You will be using that wherever I use “
Unmount the SD card
diskutil unmountDisk /dev/diskNN
Write the image to the SD card
sudo dd bs=1m if=/path/to/image.img of=/dev/diskNN
You will be asked for your password and then it will appear to do nothing for quite a while, eventually it will finish and report the number of blocks written.