I couldn't find any instructions on how to replace the driver's side rear door check on my 2004 Vibe, so I took some pictures and I'll post them here to help others.
For removing the rear door panel this video on replacing a rear door handle is very useful.
This is *extremely* similar to the front door check, so if you know how to do that you can probably tackle this without help. Gonna go 5 pictures at a time here since that's the attachment limit.
First remove the screw that is behind the small cover above the door handle:
Next remove the screw that is inside of the door pocket:
Now pull the door pocket straight up and out; it might take a little coaxing:
Take note that there are alignment holes at the bottom of the door pocket; you'll need to align the pegs on the bottom of the pocket with these when re-installing the door panel.
Now start removing the door panel. It's held on quite firmly with body clips; I used a non-marring body panel tool.