Its easier than it may sound…
A video showing how to make your own ESC flashing tool:
https://www.youtube.com/watch?v=t5unHRB2sV4
The document with ESC specs/flash database
https://docs.google.com/spreadsheets/d/13tMlu5ldLNpZXwbe6UhDHJhcgTVuljm8HDiDp9WO9Pk/edit#gid=0
