First you'll have to remove the seat. Lowering the top will give you plenty space to work in.

Slide the seat belt out of the seat belt harness.

The seat is held in by four 14mm bolts (B) which you'll need to remove. Slide the seat back to get at the front bolts, then slide it forward to get at the ones in the back.

The only thing left holding the seat in place is the seat belt sensor. It's a tiny gray plug attached to the bottom of the seat. Unplug it - It took some fiddling when I attempted it but it shouldn't be too bad.

Now you can lift the seat out of the car. The rail attached to the bottom of the seat is full of sharp metal edges, so be careful not to let these come in contact with your interior!

Start by resting the seat on a mat with the left side up.

Pull the plastic handle off of the adjustment lever. With enough force it will slide off.

Undo the two screws holding the plastic cover on (Honda part #4120-S2A9-0000, just in case you need a new one for some reason)

Slide the cover off. It won't simply slide off, you'll need to maneuver it somewhat to get it off - with a little wiggling it'll happen.

Remove the three 14mm hex bolts. Once these are removed the left side of your seat back will no longer be connected to the bottom.

Flip the chair over to the right side. Note the way the seat belt wiring is routed through the rail. When putting your new rail on you'll need to thread it through the same way.

Loosen the seat belt 14mm hex bolt (already loose in the photo below). This will detach the seatbelt and it should be dangling freely.

Remove the lower 14mm hex bolt (A) on the seat rail.

Remove the two 12mm screws on the bottom.

Finally unscrew the 12mm bolt (A) holding the seat back to the bottom. Be careful from here as now all the pieces - The seat back, bottom and rail - are loose.

With everything loose slide you should now be able to slide the bottom piece and rail out of hole on the seat back's right side.

Now everything is disconnected - Put your stock rail away and rest your seat back somewhere safe while you work on attaching the new rail. Rest your seat bottom upside down (with the gray seat belt sensor pointing up) on your work mat.

The Backyard Special seat rail includes some hardware which will replace some of the stock hardware. I'll mention when you'll need to use the new hardware, otherwise you'll be using the stock hardware. Keep it handy for now.

Slide your new seat rail on your seat bottom, making sure to thread the seat-belt through in the same way it was threaded in the stock configuration. The U-bar should face the front of the seat. The new rail should be a tight fit so just use a little pressure to slide it on - everything should line up.

Grab one of the lock washers that came with your new seat rail and thread it over the 14mm bolt for the right side (near the front of the seat bottom). Bolt this back in (A).

Same with the hole on the left side, near the back of the seat bottom - Add the other lock washer and bolt it back on (A).

Reattach the two 12mm bolts on the bottom.

Now you'll reattach the seat back. Turn the seat bottom on its side with the right side pointing up.

The right side bracket on the seat back needs to slide under the bracket on the seat bottom. You'll need a bit of force to get this to happen but it shouldn't be too bad. Just be careful not to damage the plastic washer or pinch your fingers.

Use the large black allen-keyed screw (10mm) that came with your new seat rail and thread it through the right-side hole you just aligned.

Reattach the seat-belt (14mm).

Flip the seat over so the left side is pointing up. Use the two bolts (17mm) that came with your new rail to bolt the bottom of the seat to the back.

Thread the plastic cover back through the exposed lever and position it back into place. Again this might require some finesse but it shouldn't be too bad.

Use the small screw that came with your new seat rail on the front hole (the one closest to the front of the seat). Use the stock screw to screw in the rear hole.

Your seat should be one piece again. You should be able to see the difference - The chair back and chair bottom are now further apart.

You should have two 14mm hex bolts, a 12mm bolt and a small screw from the stock hardware left. Simply store these with your stock rail - you won't need them unless you go back to stock. I bagged them up and attached them to the rail so I won't lose them.

Carefully put your seat back in so you don't scrape the interior or trap the loose seat belt.

Reconnect the seat belt sensor.

Reattach the four 14mm bolts. I attached the rear bolts first, then slid the seat back to attach the two front bolts.

Re-thread the seat belt through the harness.

With the new lower position you'll need to figure out the best configuration to get comfortable. With some adjustment I was finally able to see the tach - at least, I was able to see most of it!