Interior rearview mirror - how to replace?

Mine snapped off. Found new on on ebay.
I got the mirror off but have to remove additional parts to get wire out.
I took out 2 torx screws but it's not obvious as to what is still holding it in.
I figured I'd ask here before I break something. Any advice?

Also - what is the purpose of the mirror being plugged in?

Thanks in advance.

jh