Help, help, help - 86 Nissan Pickup Heater Core Issue

[fordyota]

Help, help, help, help!!!!Need help...... My heater core in my 1986 pickup (early model, same as 85, not hard body) is leaking and needs to be replaced. I have disconnected the hoses and removed the 2 lower nuts that hold the unit in place. It appears that there is something at the top holding the heater unit in place, but I cannot see it. The Hanes manual that I have shows a screw in the top back side, but does not say how to get to it.

Does any one know how to remove the heater/heater core assembly and how to locate the screw?