Long story short - I took off the prop guards on my P3S, but reinstalled long screws. This idiotic move rendered the two rear motors inoperable -- they barely spin at startup. A little finger encouragement gets them to spin faster, but applying throttle gets them nowhere near the speed of the front rotors causing the AC to flip over. Visual examination shows damage to the motor windings directly in line with screw hole. ARRRGGGGHHH! Obviously not a warranty repair, two questions come to mind: Is motor replacement a fairly easy DIY project? If so, where would you recommend buying them? Cost? If pro repair is the better option, who do you recommend contacting for the fix? Average cost? Thanks in advance for any guidance you can provide!