I totally forgot to update this thread. I installed the lock a few weeks ago now.
The installation was incredibly easy. Total time to install was about 10 minutes.
First step is to remove the door lock lever plate. This is done by removing the two screws you see.
The next step is to install their mounting plate. You reuse the existing screws and their plate is adaptable with the slots in it.
I didn't get a good picture of this, but this is the only remotely tricky part. You have a few adapters to select from based on the maker of your lock. These adapt the lock's shaft to the August smart lock.
Lastly, the August lock simply slides down on to the mounting plate and has some little wings that lock it in place.
There was an additional step that did take a while. I downloaded an installed the August app on my phone. Then I connected it to the door. The app wanted to update the firmware inside the lock, and that took a good 15 minutes to update. The info is transmitted over bluetooth, so that is probably why it takes so long. You have to keep the phone close to the lock for this to work.
I will return with my thoughts on the lock in a week or so. The app just got updated and I want to see how the changes effect things.