To complete a firmware upgrade via SD card on your Ender-5 Pro, follow these steps.
Connect the SD card to your Mac and determine its location.
diskutil list
In my case, the SD card is located at /dev/disk4
Unmount the SD card
umount /dev/disk4
Format the SD card using FAT32 with a 4096 block size.
sudo newfs_msdos -F 32 -b 4096 /dev/disk4
Mount the SD card again
diskutil mount /dev/disk4
Load the .bin firmware file you'd like to upgrade to.
Eject the SD Card.
With the printer powered off, insert the SD card.
Power the printer on. You should see the screen power up, but stay blank (no Ender logo)
Once the upgrade is complete, the screen will drop into the normal status/home page.
You may now remove the SD card.