95 Grand Cherokee Heater control problem

[Stevevo]

I have a problem with heater controls. How hard is it to get to the control for the air ducts. I removed the middle column radio, heater control, and display panel and can see the arm is broke off the duct shaft. The white plastic arm moves when repositioning the switch but doesn't switch the duct as it is not connected. How hard of a job is it to remove the heater control from up under the dash? Thank you.

[Stevevo]

Just got to the parts. I removed the control box that is held in by 3 phillips head screws and got the arm out and it is okay but the shaft that is up inside the box is broken off in the plastic arm. I removed it but don't know how hard it is to get the shaft and box out of under the dash. Has anyone else had these apart?