I know a lot of people are smart enough to flash the device so easily. But for me and those people who are not so familiar, here is the real case after few hours of experiment. I managed to upgrade ICS 4.0.4 (feiyu).

1. First get the ROM. Search for custom ROM/kernel for Aurora. Or try here:
http://tabletrepublic.com/forum/novo-7-aurora/costum-rom-aurora-feiyu-mod-0622-a-2239.html

2. Once downloaded, I rename the pack to update.zip. Don’t need to unzip, we will use later.

3. Then I download a root script created by Tasselhof. Actually I want to use the adb command. Search for Tasselholf Android etc. Or you can go here:
http://www.tabletsdroid.com/forum/discussion/47740/ainol-novo-7-aurora-root-and-android-market-fix/p1

4. Then I download another script which is called custom recovery Clockworkmod.

5. Now, let start to work by creating desktop/novo7 folder.

6. Put update.zip into novo7 folder.

7. Extract Tasselhof script into novo7 so you will get adb command in that folder.

8. Extract Clockworkmod into novo7 so you will get recovery.img, install-recovery.sh & reboot-recovery.sh in that folder.

9. In command prompt type this:

adb root
remount
adb push recovery.img /sdcard/
adb push install-recovery.sh /sdcard/
adb push reboot-recovery.sh /sdcard/
adb push update.zip /emmc/
adb shell chmod 755 /sdcard/install-recovery.sh
adb shell chmod 755 /sdcard/reboot-recovery.sh
adb shell
cd /mnt/sdcard/
sh install-recovery.sh
sh reboot-recovery.sh

10. Now, your device will reboot and Clockworkmod will execute. Select menu “install update from sdcard”. Then select “from other folder”. Then browse to “/emmc/”. Then select your “update.zip”.

That’s how I did it.