Lol sorry guys, I didn't know there were more of you. I found out this could work by Googling and my own creativity (I'm the kind of person that restarts and hopes it will work)
- Copy the downloaded 18MB update file and rename it to update.zip, copy it to your device (you already did that)
- Delete all backups in ROM manager (it's under Manage and Restore Backups)
- Uninstall ROM manager and install it from Play store again
- Flash ClockworkMod recovery in ROM manager
- Backup current ROM (it's gonna take a while, I don't even know why I did this, I guess my paranoia)
- Once Android is up again, go to ROM Manager and tap the second option (Reboot into Recovery). It should boot into recovery, now just select apply update.zip
I have no idea how this works, all I did was reading and reading, and decided to try this out. As I said, I'm the kind of person that hopes restart and rewipe will do it, and this time it did. I have 4.0.4 now.
I hope it works for you, I know this is pretty much unprofessional, BUT IT WORKED FOR ME.
Please let me know, and good luck, and sorry for not posting this, I didn't know there were more of you.