Shifter is removed from inside the vehicle, no need to go under the car at all.

Search YouTube for the "Barton Shifter Install Challenger".

 

While removing the shifter from up top is usually done.. to remove the 2 pins that connect the shifter forks to the tranny it is easier to access them and install them from the bottom of the car.

the passenger side is a real bear.

chris

 

Pinch the boot between your thumb and finger and give a small jerk upwards, one side at a time. The trim will pop right up.

 

Here are the instructions from the service manual. I added the manual trans removal section as well

 

NO, removing the transmission to replace the clutch does NOT mean you must remove shifter, once the connecting bolt to shifter/transmission rod and the two forward pins are removed, the shifter is left attached to car by rear bolt, NP.