So you know how the 'shelf' in the back is supported by two string thingys on either side? Well, one of the screws behind the clip that the string thing is seated over became loose and separated from the plastic clip. The screw has now fallen somewhere behind the tailgate lining. Are there instructions anywhere on how to propery remove sections of the tailgate lining? I already tred to remove the small portion where the string thing clips into, and it seems like I could just pop it out but before I go yanking things apart and possible causing damage Id prefer to see if anything has been documented on the subject.

 

Get one of those magnetic pick up tools, pop out the piece you describe and go fish the screw, no need to remove everything.
I don't know if it pops out, but that's usually the case with those plastic panels.