Here's the steps I used:1. Make sure the file is on the root of your SD card (not internal storage). That is SD-EXT2. Power phone down3. Reboot into stock recovery (adb reboot recovery) by holding Power and Volume Up/Down at the same time.4. When the robot appears, press both volume keys in at the same time.5. Select “apply update from sdcard” using the volume keys, then Power to initiate it.6. Using the Volume keys, choose the file that you downloaded above, press Power and let it load.7. When the install is done, press Power. It'll reboot, but it'll be longer than normal (a few minutes)What you were missing was step #4, as mattyj24 and dpw2atox suggested.