No problem--that's what we're all here for

.
Okay, all that does indeed line-up.
So, to re-root, you'll need to flash the su.zip file from ClockworkMod custom recovery. So, if you don't have CWM (ClockworkMod) already flashed, you'd have to re-flash that first (i.e., get the custom recovery installed).
Here's a quick summary of the steps to do this manually:
-
download the su.zip that's appropriate for ICS 4.0.4 and transfer it the top-level of your /sdcard directory
-
make sure you've got your fastboot USB drivers installed
-
make sure you've got the fastboot utility available / installed
-
boot your phone into fastboot / bootloader mode
-
flash or soft-boot ClockworkMod custom recovery
- flash the su.zip from CWM that you downloaded earlier and put on your /sdcard
- reboot and enjoy being rooted
All of these steps (and more) are outlined and documented in this thread:
http://androidforums.com/verizon-galaxy-nexus-all-things-root/474570-how-all-things-root-samsung-galaxy-nexus.html
(thankfully, you've already got your bootloader unlocked, so you don't have to hassle with that)
You could do all of this manually, however you might want to check-out
Wug's Galaxy Nexus Root Toolkit since it automates these functions for you.
The downside is that I've never actually used that utility

(LOL, I've always done things manually myself

).
I'm certain is an easy, friendly tool, but I can't guide you through how to use it since I've never done so myself. Perhaps one of the other fine folks could chime-in with a few words of encouragement (pro or con) for using Wug's Root Toolkit?
~ ~ ~
Note: I would caution you that at this time, installing a JellyBean ROM has proven problematic for even some experienced folks. It might be best to simply wait for the JB OTA, but there's no telling how long that might be...
Cheers and I hope this helps!
-SA