First post here... but I've repaired these door locks, its not hard, buy it is time consuming and a little frustrating if you're short on paitence.
They're driven by a pair of small DC motors. As they get old, the comutators block up with carbon dust from the brushes. If you are going to the trouble of pulling the door lock out to replace it, you might as well have a go at repairing it first.
If there is noise coming from the lock but it won't open, its probably this issue.
If no noise, likely the wiring loom / body control module issue.
BTW, if the door won't unlock when stnading beside the vehicle, try starting the engine and rev it a bit while using the unlock button inside the car - this will feed a little more voltage to the motor and might just get you out of trouble in the mean time. Not sure how to post pictures here yet...