The first post (Step 2) should be definitely corrected to support ICS tablets.
After several hours I could bring my Archos back into usable state. Workaround for the steps:
6. Download
archos.ext4.update mentioned
in this post.
7. Decompress the file archos.ext4.update and put in into internal storage. If your tablet is still booting you should be perhaps able to connect it with adb. So try
Code:
adb push archos.ext4.update /mnt/storage
8. Download zImage and initramfs.cpio.lzo mentioned in the same post
...
13. Copy downloaded two files into new drive
14. The device start will start 4.0.6 update and then boot with root privileges; no more actions are required. abd shell gives you root, superuser is installed and functioning.
Hope that helps.