How to force update 4.0.4 for Galaxy Nexus
Tip: How to Force the 4.0.4 Update for the Galaxy Nexus LTE – Droid Life
1. From phone, head into settings>Apps>All
2. Search for Google Services Framework
3. Once found, tap on it and choose "Force Stop."
4. Then choose "Clear Data"
5. Back out of Apps to your About Page in Settings and check for System Update.
May have to repeat a few times.
Will be following these instructions in a few minutes to see if it works. If anyone else wishes to try, good luck and let us know how it goes!
UPDATE: Wasn't able to try the above instructions. Got to my phone and it was 75% done downloading the update.