You have to understand that you'll flash the device at your own risk and it could be out of order after flashing.
1. Charge your tablet to a full charge
2. Download firmware
3. Unzip A8HD2.3.4-_1.0rc4.7z archive
4. Turn off the tablet
5. Connect the USB cable
6. Press power and - (minus) volume buttons simultaneously, device will turn into boot mode
7. Install the drivers from A8HD_drv_tools/driver folder
8. Create a new folder and copy all the files from A8HD_drv_tools/tools and A8HD_fw_2.3.4- 1.0rc4/um2703-Gingerbread-1.0rc4 into your new created folder
9. Start the update-GB-1.0rc4.bat file, you'll see the flashing procedure, your screen will change colors during flashing procedure. WARNING: don not close the flashing procedure window in any case until the procedure finish, when it's ok, your tablet will reboot
10. Done, check the Android version it your tablet
(credits to synergy84)
