Why are you doing this so complicated? There is a much more easier way:
-Install Desktop Manager version 220.127.116.11
-Install version 18.104.22.168
-Close Desktop Manager
-After installation go to C:\Program Files\Common Files\Research In Motion\AppLoader and delete vendor.xml
-Start Desktop Manager
-Connect your 6710 or 6720 with 16MB to your PC and click "Next"
-Follow the instructions on the pc screen and update your device