[Update: Now With yakju] How-To: Download And Update GSM Galaxy Nexus To Android 4.1.1 Manually (Jelly Bean JRO03C)

Following yesterday's Jelly Bean AOSP invasion, the HSPA+ Galaxy Nexus is now receiving the release build 4.1.1 (JRO03C) of Jelly Bean. That's indeed great news, but since the rollout is usually staggered, not all phones are allowed to receive it the second it's out there. If you're rooted or have an unlocked bootloader, why not just bypass the line and flash the update manually? I just did, and it took only a few minutes.

Prerequisites

Update 7/11/12 4am PT: we now have yakju!
Here's what you need to have for this method to work (I will update the post if we figure out the links to OTAs for more variants):

• takju - this is the GSM variant sold directly by Google and given out at I/O 2012. Your device needs to be running either:
  • JRN84D (Android 4.1) or
  • IMM76I (Android 4.0.4)
• yakju - this is the international unlocked GSM variant.
  • IMM76I (Android 4.0.4)

If you're unsure whether you have takju or yakju, open up /system/build.prop in your favorite file viewer and see what it says there.

End Result

Here's what you will have after the flash: Android 4.1.1 JRO03C.
Note: The update does not wipe your data.

Download

Note: these downloads are coming directly from Google. They're the official OTAs, not custom ROMs.

• takju
  • takju-JRO03C-from-JRN84D (8,914,753 bytes, MD5: d92ba952c528be672ec29f05c1a672bd)
  • takju-JRO03C-from-IMM76I (154,343,776 bytes, MD5: 4898d7e3cdd246674d02d5563d69a634)
• yakju
  • yakju-JRO03C-from-IMM76I (151,966,582 bytes, MD5: 81ac79422f7704e46f792944693080ce)

Install

Note: First of all, the bad news - if you're not rooted or don't have an unlocked bootloader, you will have to wait for the OTA. There's no way to manually flash update files with full stock, which is definitely a bummer, but unfortunately it's true. The good news is that you won't have to wait long. Or just unlock your bootloader - it's stupid easy.
Rather than provide the installation steps here, I'm going to refer you to this XDA post which contains excellent instructions for every combination of recovery and root status you can think of. Here are some pictures to guide you along the way (using CWM Touch).

  

Happy flashing and welcome to Jelly Bean!
Thanks, Karl!