I initially had that thought for the motor, too, until I got that sucker out of the door and into my hand.
They engineered it in such as way as to make it impossible to repair or rebuild. You cannot open it without destroying it. Cute.
Plus, a locked-up solenoid would be fairly trivial to bypass. This door was designed so that when the motor locks up, you cannot manually lock the door. That's just bad IMO.
I think, before going through all of the trouble to attempt to repair a locked-up solenoid, I'd just replace it with a $10 aftermarket one (of the type used to add keyless entry to cars without power locks).
I imagine it's really fun when a solenoid locks up in the locked position (with the door closed, naturally).
I'm pretty sure that my '96 Contour (which uses motors for the door locks) is designed so that a motor failure or lockup will not prevent the door from being locked. (It works fine with the battery out and you do not hear the motor moving at all when you lock or unlock it in that condition).