Step 1:
Remove the Helio from the cradle.

Step 2:
Hard reset the Helio by pressing the RESET button and ON button for about 1
second.  Release the ON button and then RESET button. The Helio is ready to
enter the boot loader now.

Step 3:
Enter the boot loader by holding the UP button and then ON button for 6
seconds. Release both and press the DOWN button. You should see the Helio
show "Boot Loader" on the display.

Step 4:
Place the Helio in the cradle and make sure that the cradle is connected to
the PC.

Step 5:
Run dt.

Step 6: 
Wait around 4 minutes, or until you get the message "Write Check
Complete !". If it takes longer that 7 minutes, interrupt dt and start
over from step 1.  Try a fresh set of Duracell Ultras if you have
repeated failures.

Step 7:
If using Linux, just hit reset.  If using VT-OS, hard reset
the Helio (see step 2).  You can check the OS version from the System
Information in the System Setup application.