I have now successfully replaced the driver's side key door lock with a replacement I found on eBay. The total time for this was in the neighborhood of four *%$#@ hours, and I honestly don't know how I could have done it faster. I now know where there are NO YouTube or other videos online: it's because it's nearly impossible.
Without shooting videos inside the door's sheet metal, it's really difficult to describe what we ended up doing, but here's the challenge in a nutshell: it's very difficult to remove the door handle AND the key lock at the same time, especially since there is an actuator rod that runs between the door handle and the latch? locking mechanism? that eventually holds the door closed. Removing this actuator rod is very difficult, and has to be done blindly by reaching into the recesses of the door.
One you get the door handle removed, you have to figure out how to get the lock mechanism out of a hole that seems to be smaller than the mechanism itself. When you replace the new keylock mechanism, you have to insert its rotary actuator into a four sided socket that looks like a giant Phillips screw head, which is inside the door.
Suffice to say, we finally did it (my wife acting as the iPhone flashlight holder), but it was a bear. If there is someone out there who has either a) a better technique, or b) a better explanation, I would love to know what it was. So many dead ends, so many bruised knuckles. Luckily the part was on ly $22 on eBay and worked as promised.
Chuck Hawley
It's actually my daughter's HR-V and she'll never appreciate what I went through...