Hopefully posting a link to this doesn't contravene any forum rules...
Here's my .NET project to do an OTA FW Update for a S6B module:
Command line syntax is very simple:
S6BFWUpdate [ip-address] [fw-file]
S6BFWUpdate 192.168.0.100 C:\XB2B-WF-2026.ebin
I've include the full source and a .NET 4 compile. Please feel free to use and/or modify for whatever purpose you see fit.