D-Link DIR-600 rev B2

Overview
DIR-600 H/W rev. B1 hardware are same as in D-Link DIR-300 rev B1

How to open the DIR-600 (see pictures): Remove the two mounting screws that are located under the rubber paddings. The top cover is secured by 4 latches on three sides. Use a flat head screw driver to open the latches to the left and right, then lift off the top cover. Be gentle with these latches as they can break very easily.

Links of Interest
On the DD-WRT supported devices table

Device page in DD-WRT wiki

DD-WRT Screenshot on the DD-WRT forums (showing 1C:7E:E5 OUI)

Device page in OpenWRT wiki

On the OpenWrt forums

Pictures
Zerohero Images