How can I install the newest EFI firmware upgrade from El Capitan?

Solution 1:

First check your current Firmware and SMC version About your Mac -> More -> System Report. Check the Boot ROM and the SMC version. It should look similar to this:

The latest Boot ROM version for your MacBookPro8,1 (Early 2011) is MBP81.0047.B2A and the latest SMC version 1.69f4 (SMC 1.7).

If you get the same versions the latest EFI updates are already installed.

The most secure method is to swap the internal hard disk with a spare 2.5" drive and install Mountain Lion or Mavericks.

Then download Mac EFI Security Update 2015-001 and install it.

After a reboot the firmware will be updated. Shut down your Mac after the successful update and swap the drives again.

Recheck the Boot ROM version and the SMC version.

Solution 2:

WARNING: THIS COULD POTENTIALLY MAKE YOUR COMPUTER UNUSABLE IF THE FIRMWARE DOESN'T WORK PROPERLY. Please make sure you know what you're doing before continuing.

Manually Flashing The Firmware

1. Download the firmware installer.
2. Unpackage the package. Find the installer app.
3. Locate the firmware within the app's contents. It'll have a name like "MB51_007D_03B_LOCKED.scap"
4. Run this command sudo bless -mount / -firmware /Applications/Utilities/NAME_OF_FIRMWARE_INSTALLER.app/Contents/NAME_OF_FIRMWARE.scap

This should restart your computer and flash the firmware.

Change the Version of OS X Your Computer Thinks It Has

1. If necessary, turn System Integrity Protection off.
   1. Reboot into Recovery Mode
   2. Open Terminal under the Utilities menu
   3. Type csrutil disable
2. Navigate to and open /System/Library/CoreServices/SystemVersion.plist
3. Change ProductUserVisibleVersion and ProductVersion to a valid version of OS X (such as 10.9.5)
4. Optionally, reverse the steps above (csrutil enable for SIP back on)