Typical introduction to XeThru modules are best supported using XeThru Explorer, which will demonstrate the module use and perform firmware upgrade automatically.
As an alternative, it is possible to use Module Connector or any other custom implementation of the serial protocol to do module firmware upgrade in a scenario where the modules are deployed. In this case, you need the module firmware file that is used during firmware upgrade.
This package contains the X4M300 and X4M200 module firmware for such upgrade, with release notes.
Annapurna Firmware 1.4.7
X4M300 and X4M200 module firmware with release notes used for deployed FW upgrade