Quoted from MurphyPeoples:

Out of curiosity what mac do you have? Granted my iMac is 4 years old but it is running the latest ios, and it ran Unebootin fine.

Quoted from rgzpinx:

I just download the update and dump the files on a usb jump. Never installed something else on a few different newer Macs.

Quoted from KingBW:

For MAC, try this below. I don't own a MAC, but Joe Katz gave this information out recently to people with the same issue. If it works for you - great!
Step 1
-- Download the full install .iso file
Step 2
-- Start Disk Utility in Applications/Utilities,
or type "disk utility" into the spotlight search bar (magnifying glass in upper right of screen)
-- If needed, click on "View - Show All Devices" to see all of the devices and their volumes on the left side.
Step 3
-- Insert USB stick, and once it appears in the sidebar of Disk Utility, highlight the device name, not the volume name.
-- Click "Erase" button and set the format to "MS-DOS(FAT)" using scheme "Master Boot Record" with name "JJPUSB"
-- Click "Erase" to start the formatting process.
Step 4
-- Double-click the previously downloaded .iso image file from Step 1
-- This should mount the iso file and open a Finder window showing its contents
Step 5
-- Open another Finder window and on the left side click on the name of the USB stick you formatted in Step 3,
which should show a blank window because there are no files on it yet.
Step 6
-- Select all of the files in the iso file Finder window from Step 4, and drag them into the empty Finder window
from Step 5. This will take some time (20-30 minutes) to complete.
Step 7
-- Once the copy is complete, click on the little "eject" triangles next to the iso image name and the USB stick name
on the left of a Finder window.
-- Once the names disappear from the Finder window, remove the USB stick from the computer.
Step 8
-- Use the USB stick to install the new version in your game, etc.

Quoted from KingBW:

For MAC, try this below. I don't own a MAC, but Joe Katz gave this information out recently to people with the same issue. If it works for you - great!
Step 1
-- Download the full install .iso file
Step 2
-- Start Disk Utility in Applications/Utilities,
or type "disk utility" into the spotlight search bar (magnifying glass in upper right of screen)
-- If needed, click on "View - Show All Devices" to see all of the devices and their volumes on the left side.
Step 3
-- Insert USB stick, and once it appears in the sidebar of Disk Utility, highlight the device name, not the volume name.
-- Click "Erase" button and set the format to "MS-DOS(FAT)" using scheme "Master Boot Record" with name "JJPUSB"
-- Click "Erase" to start the formatting process.
Step 4
-- Double-click the previously downloaded .iso image file from Step 1
-- This should mount the iso file and open a Finder window showing its contents
Step 5
-- Open another Finder window and on the left side click on the name of the USB stick you formatted in Step 3,
which should show a blank window because there are no files on it yet.
Step 6
-- Select all of the files in the iso file Finder window from Step 4, and drag them into the empty Finder window
from Step 5. This will take some time (20-30 minutes) to complete.
Step 7
-- Once the copy is complete, click on the little "eject" triangles next to the iso image name and the USB stick name
on the left of a Finder window.
-- Once the names disappear from the Finder window, remove the USB stick from the computer.
Step 8
-- Use the USB stick to install the new version in your game, etc.

Quoted from KingBW:

You're still going to have to manually check to see if there is an update from a machine menu option via WiFi (or checking like you do now), but it will download and update automatically in the very near future. Testing is in progress. It's really nice.