beagle bone black booting over usb

“Hi everyone, I’m trying to program the eMMC on my BeagleBone Black directly over microUSB without using an SD card. I’ve read about booting the board in a specific mode that allows USB mass storage access, but I’m unsure how to achieve this. Could anyone guide me on how to boot the BeagleBone Black so that it’s recognized as a mass storage device over microUSB? I’m looking to flash an image file to the eMMC. Thanks in advance for any help!”