Need to see overflow pics

[reefrubble]

I have an acrylic tank , with an internal overflow . I want to cut out the internal overflow box , and put an external overflow box on the back of the tank . I will have to cut a slot in the back wall , going into the external overflow box . If anyone has any pics showing this slot ,could you post them . I would like to get an idea how to layout the slot . TIA Ted