.....WOW...........
At glance: this is a serious...very serious job....
THe A/C must be evacuated and the A/C core removed before you can pull out the heater core. ...eh...sorry about that, chief.....( Maxwell Smart...for those who remember)
There are fantastic photos provided by another forum member....hld on, I'll find them....
OK...check
THIS out..and read the thread throughout..there are a lot of good advices...specially about the air bags...