I just did the same on my R53 and installed the CAE shifter, which is essentially the same as the Coolerworx. Procedure pretty much the same for R53 also. Your video helped a lot, thanks very much for posting!
I installed the seats a couple years ago. Because of the limited space they are a pain to get in and out, so I don't plan on taking them out anytime soon. All I'm doing from here on out is making sure the bolts stay tight. Seat install is pretty simple though. Four bolts hold the seat to the floor, remove them and unplug the wiring harness that connects to them. Get a seat bracket (I used Planted) and bolt that in place. Bolt the new seat to the bracket.
