I've recently experienced difficulty closing the rear hatch. it use to close easily from full height, now it needs to be lowered and slammed hard to engage.
Opens with a slight rub, my wife slammed it a few times once when it wouldn't lock. Took it to the dealer, $380+ to fix, parts/labor. Seems a bit much, lock cost about $180+/-. Is this a hard replacement? Is there some place to go to get info on how to do it?

"Opens with a slight rub"

It could be that the screws that hold the lock in place came loose. Happened to me.
You will have to take the cover off the hatch before you can do anything. Not very hard now that it is warm outside. Just be careful and try not to break any of the plastic fasteners. Remove the bottom portion first, then lift the whole panel up and off.

http://volvospeed.com/Repair/tailgate_trim.php

The link shows how to get the tailgate cover off. It is confusing because he uses top and bottom wrong.
When the panel is off, just use a T40 driver and check that the 3 screws on the bottom of the latch are tight!
Remember, when putting the panel back on, slide the top next to the window on first, and then hit the bottom with the heel of your hand to get it on.

Klaus