gprs shield sim900 firmware upgrade

HI,
I have the GPRS shield V2 with sim900 module. How do i upgrade the Sim900 module since it is part of a shield?

Any help is much appreciated.

Richard.

Please refer to the resources of GPRS shield v2 : SIM900 firmware and tool(firmware:1137B08SIM900M64_ST) for firmware upgrade (seeedstudio.com/wiki/GPRS_Shield_V2.0)

Jacket