Heater Core In Arizona??

Okay ..BLIMEY! Now that you've had your laugh... 'Ello Hypnoking here ..Can any member e-mail me a diagram for removal/installation of a heater core on a 1985 chevy C-10 Scottsdale ? 350 V-8. Chiltons and Haynes are no help at all BULLOCHS! They only list a description of the procedure The problem is simply removal of the box. The bottom two studs into the firewall go nowhere and I cannot locate the bolts . I'm a hypnotherapist by profession however not an idiot when it comes to repair, I'm just visual a diagram would be greatly appreciated. ...Yes it does get cold here in the desert during Dec-Feb. Ta