How do you remove dashboard to get to evaporator/heater core?

[waldeaux]

looking for help on how to remove dashboard in a 99 suburban? I need to replace the evaporator and heater core. I tried removing it from the bottom box, but cover won't come off. I was told that you have to from the dashboard. Is this true? is there an easier way? The dashboard won't come off. So for I tried to take apart the bottom of dash and unscrewed the the steering colum and pulled it apart. There is a metal bar that goes left to right that is in the way of the evaporator/heater cor area. I have taken out the front 2 seats (to make more room to work). I have disconnected alot of wires and unscrewed alot of screws. I have been trying to get this dahboard off for 2 days with no luck! Any info. would be great.