Flashing Android M Developer Preview on Nexus 9

I got a Nexus 9 tablet from Google I/O, which is really exciting because that means I have a device to install Android M Developer Preview. Google is hosting What's New in Android: Hack@Home this Friday to talk about M, so I want to make sure my device is ready before then.

I took a video of the process:

For those of you who prefer text to video, here are the steps, mostly from https://developers.google.com/android/nexus/images#instructions:

1. Download the volantis image from https://developer.android.com/preview/download.html.
   Unzip it (tar -zxvf filename.tgz on linux). Navigate to the unzipped image directory (For Nexus 9, it starts with volantis).
2. Become a developer by tapping Build Number 7 times.
3. Enable USB debugging.
4. Important! Enable OEM unlocking.
5. Run adb reboot bootloader.
6. At this point your device is OEM locked:
   
   Run fastboot oem unlock.
7. Press volume up to confirm unlocking the bootloader:
   
8. Now your device is OEM unlocked:
   
   Run flash-all.
9. Wait for 5 minutes or so.
   
   And voilà! A dialog warning you that this is a preview. Exactly what we want.
10. Lock again with adb reboot bootloader, then fastboot oem lock, then disable OEM unlocking from developer options after reboot.