How can I get the actuator for blend door off

[dcdyd]

I am trying to get the actuator of blend door off to check whether it works or not. My A/C blows less colder air and I am not sure whether it is due to the blend door or lack of freon. So first I would like to check the blend door. The actuator is fixed with three screws. Two are in the front which you can see from the below picture. One is on the back. I wonder what kind of the tool I can use to get the back one unscrewed. The clearness from the top is only about 1 inch and half. I tried all hand tool I have and nothing seems to work.

Some say that the actuator can be pryed off but unfortunately mine is not the case.

 

[SoNic67]

Cut an 8mm offset wrench in half.
Remove the front two black screws.
Squeeze your hand, with the wrench, in back (over the top of actuator) and try to unscrew the back one. Work by feel. I got it several turns up in 30 minutes and then, with hand bruised and cramped, I give up and cut the plastic support of the screw, under the actuator, with a long saw blade. If you have a child with smaller hand and enough hand coordination, you might be in luck
The new actuator came with the improved version of snap-in adaptor plate that is found in newer vehicles - you cannot use that here, just discard it.
Rotate the "hole" that moves the internal plate, by hand (I used my finger), to match the position of the new actuator. My truck was parked sligtly leaning on a side of the road and the plate was moving by itself in a wrong position. Had to move my truck on the other side of the road, where it was flatter, so the plate stays in place.
The new actuator stays and works perfectly with only the front two screws.
Reset the ETAC after installing.

For the test mode, press "OFF" and "FLOOR" in the same time, then release and press "AUTO" (within 2 seconds). "DEFROST" clears the codes - but it won't work if the actuator is broken.
I did have error codes 024 and 025 when a gear was broken inside the actuator itself.