Thanks to the user community around the Xiegu G106 and G90, there are some really clever ideas and software out there. This video by KM9G outline an easier way to update the firmware on your Xiegu G90 and G106 transceiver.
Direct link to written instructions and the software.
Link to download latest firmware.
NOTE: Please keep in mind that using third party software and firmware isn’t supported by Xiegu or Xiegu.eu, you have to contact the author of the software for help should you need it.