heater core blew up in my truck yesterday and today i tryed to change it. so far i took glove box out and blower cover but i dont know how to get the cover off the heater core. so anyhelp on how to do this would b nice. does the dash have to come out and do i have to pop the rivets off the cover to get to the core? its a 74 f250 4x4

 

The dash doesn't need removed but taking out the right bolt on the bottom end of the dash and pulling the dash forward does give you some additional clearance.