How exactly do I prepare a usb stick for a firmware upgrade?

[userKS3eNDBxpJ]

I have MacOS.  I downloaded the latest firmware for my G95C monitor.  It was a zip file that expanded into a .img file.  I didn't find any info on what to do with that img file.  Do it just place it on the thumb drive or do I need to 'expand' that into the usb?  

[LongHiker]

@userKS3eNDBxpJ The USB drive needs to be formatted as FAT 32. 

You can use Disk Utility on your Mac to format the USB drive.