1. From your Linux or MacOSX web browser, bring up this post. That way you can click on the links and copy/paste as you follow along with these instructions.
   
   
2. Go to the N810 software download page.
   
   
3. Enter the Product ID (WLAN#) for an N810 device. For the Product ID you can use any number between 001d6e9c0000 and 001d6e9c9999. (credit to TPC) Then on the next page click "I accept".
   
   
4. Download the latest firmware file
   RX-44_2008SE_1.2007.42-19_PR_COMBINED_MR0_ARM.bin
   and save it to a directory that you can easily find later.
   
   
5. Go to the Flasher utility page and click "I accept".
   
   
6. Download the latest firmware-flashing software for Linux (flasher-3.0) or MacOSX (flasher-2.0.macosx) and save it in the same directory as the firmware file.
   
   
7. Start a Linux or MacOSX terminal session window and change directory to the location of the two files you just downloaded.
   
   The commands in the next instructions will all be entered at the terminal session command prompt. These instructions are for Linux users, but the MacOSX instructions are very similar - Just substitute the Mac flasher program name in place of the Linux one.
   
   
8. Enter (or copy/paste)
   chmod a+x ./flasher-3.0
   to make the flasher file be executable.
   
   
9. Enter (or copy/paste)
   sudo ./flasher-3.0 -u -F RX-44_2008SE_1.2007.42-19_PR_COMBINED_MR0_ARM.bin
   to unpack the components. If prompted, enter the password for the Linux/MacOSX system.
   
   
10. Turn on your N800. Unplug the AC adapter (if you were using it) and check that you have a good battery level before you proceed. Leave the AC adapter unplugged.
    
    
11. Switch off your N800. Don't simply lock it... it must be powered off.
    
    
12. Using the USB cable that came with your N800, connect it to the computer.
    
    
13. Hold down the HOME button on your N800 (the one with a house icon) until you complete this next step. Now also press and hold the POWER button to turn the N800 on, but do not release the HOME button just yet. Keep holding the HOME button until your N800 shows the white NOKIA screen with a small USB icon in the top right corner of the N800 screen.
    
    If your N800 booted normally (to the home screen), then turn it off and repeat the last step until you get the correct boot screen with the USB icon.
    
    
14. Now enter (or copy/paste) the following three commands in the terminal window to transfer the firmware to the N800:
    sudo ./flasher-3.0 -f -k zImage
    sudo ./flasher-3.0 -f -n initfs.jffs2
    sudo ./flasher-3.0 -f -r rootfs.jffs2
    
    
15. When all three transfers are completed, enter (or copy/paste)
    sudo ./flasher-3.0 -R
    to reboot the N800.
    
    
16. You can now disconnect the USB cable. In a few moments the N800 should start to boot up normally. You will then be prompted to go through the initial setup procedures as if it were a new tablet.
    
    Congratulations, you are running OS2008!