I have an old Magic Chef heat pump. Model #PWC24E9.2-1. After testing the other components regarding defrost - relay & timer, it seems to be the sensor. Is there a way I can replace this part without pulling the entire unit out of the wall to gain access to the condensor/coil where the sensor is located? It is the type of sensor that uses a capillary tubing to sense the temperature, this tubing is attached to the defrost timer.

Thanks

Remove from wall. Repair and place back in wall. Probably not what you wanted to hear but that is the way it is.

How difficult would that be to do? Difficulty level?
Aside from the obvious... disconnect duct, wiring, bolts/screws? Does the unit slide on the chasis/drip pan? Do I have to worry about it tipping over. The way it is installed, it sort of 'floats' off the floor, there is no support from floor to unit, just the square chasis/drip rail.
And if I did slide the unit out, what else would you recommend I do to it while I have it out? Maintenance/repairs/upgrades?

Thanks

You will need some help there. As far as the rest of it goes I believe you will find that sometimes you just cannot replace the sensor. Many times you have to replace the control.
The rest of the service is just the usual HVAC stuff clean and lube.
A adjustable auto floor Jack and some wood blocks will be handy to set the lip of the unit on when partially removed.