If anyone else is wondering how to turn on the 12V supply, you short the 2 small center pins together. The outer rings are ground, and the inner rings are the +12V. The two small pins are the +5Vsb and the 12V enable pin, which turns on the 12V when pulled up to 5V

This guide is also applicable to the 600 series

If you don’t have one of these plastic tools, I’ve had good luck just prying up from the back with my hands