Next, I removed the bottom seat cushion by removing two T20 screws from the front of the plastic seat bottom. There are normally two plastic non-removable (at least not without breaking) fasteners that attach the seat cushion to the plastic seat bottom, but these were previously sacrificed when I removed the cushion months ago to dye it.
This next part is a little tricky and difficult to describe. There is a cable that attaches the front of the buckle assembly to the seat bottom. See the photo? Place a slotted screwdriver near where the red arrow is pointing, underneath that horizontal black plastic piece and gently pry upward. The goal is to lift that plastic piece up slightly so that it can clear the metal vertical piece circled in blue. Once you've lifted it up high enough, slide it in the direction indicated by the blue arrow. You can now easily removed the metal hook at the end of the cable from the eye circled in yellow.
With the zip-ties cut, the nut removed, the cable disconnected, and the bottom seat cushion removed, you should be able to easily pull the entire assembly off of the seat.
The next step involves harvesting the seat buckle from the donor seat.
Here is how I removed those plastic fasteners. There are two of them, both on the rear section of the seat bottom, one left side, the other on the right. Snips and a drill were required. I snipped off what I could and drilled just enough to free the seat cushion.
