I've puled two in the past three days.
The easiest and best way to get the actuator out in lieu of removing the dash is a modified version of SSE motorheads directions, to remove the lower hush panel, pull the MALL module (module laying on firewall with two connectors, one is light blue), then remove the two 7mm screws holding the HVAC Programmer tot he heater box, unclip the hook for the vaccum lines to it and disconnect the large red wiring connector then lowering it slightly slide your hand/arm up behind the HVAC Programmer and feel the top of it for wiring. Follow that wiring to the actuator and pushing from the passenger side to driverside use your finger to push in and up on the connector/ wiring. You may now safely lower and tuck the programmer out of the way. Then using a 5.5mm socket, 6 inch 1/4" extension and 1/4 ratchet remove the two 5.5mm screws holding the side of the heater box to the main HVAC ducting. You will easily see the lower screw once the HVAC programmer is removed, the top screw is in the same location as the lower about 4-6 inches above. It is a blind screw in that you can not see it from below.
With the heater cover loose, pull back the carpet and padding from that area of the floor, then wiggle the cover down and out. Replace actuator and restore cover to it'* original location. Slide programmer into the general area and hook up the connector to the actuator and the main connector to the programmer.
Looking through the access hole located behind the glove box, set the heater flap arm to full right (pass side) and lay the new actuator rod on top of it. Start the car and select max heat. In approx 45 seconds the actuator should swing and find it'* home position. Once it has done this clip it into the heater flap arm and change from hot to cold etc waiting a few moments between changes for the arm to move.
00 Regal GS: All kinds of cool stuff.