I made this DIY thread for another forum (Philippine Jazz and City United) two months ago. Decided to repost it here to help DIYers install their seats or just remove the stock ones for any reason.
The obligatory disclaimer:
Remember, neither myself nor IB, nor FitFreak.net are to be held liable for any problems that may arise from following this DIY. Please use common sense, and proceed at your own peril!
(Thanks Sid 6.7 for the disclaimer

)
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The Recaro SRD semi-bucket seats are arguably best known as the items that came stock with the DC2 Honda Integra Type R and the EK9 Honda Civic Type R. Not many people know, however, that they will mate perfectly with Bride's classic RO-type seat rails. While people have told me that I could have had seat rails fabricated from my stock GD1 Honda Jazz seats, I opted to perform the install myself and with more purpose-made equipment.
You will need the following for this seat swap and install job.
1. 6x25mm bolts x12 (available at motorcycle parts stores) or M8x25mm button-cap bolts if available
2. Bride RO-type seat rails
3. Bride seat anchor bolt (this, and all its washers and nuts comes with the seat rails)
4. Recaro SR-series or L-series seats
5. ratchet wrench handle
6. sockets: 10, 14, 18 and 22mm
7. long-nose pliers
8. claw hammer
9. screwdriver
10. Allen wrench set
The first thing you want to do is to remove the tough polypropylene "foot covers" that cover the mounting bolts of the stock Jazz seats. All you need to do is pry them off, starting with the inner side.
Due to the fuel tank located under the front seats, each of the Jazz's front seats has three normal feet and one flat foot located in the forward inboard side. Most of the foot covers are easy to remove, but the ones on the flat foot are quite tough to pry off. I've taken a photo of the passenger-side foot covers removed, with their approximate location with regard to the seat itself.
With the foot covers removed, snap on your 14mm socket to your ratchet wrench. Loosen the four heavy bolts that secure the stock seats to the Jazz's floorpan. Keep these bolts; you'll need them when the Recaros go on.
Driver's seat, left-front

Driver's seat, right-front

Driver's seat, rear
The driver's seat has a seat belt sensor you'll have to take care of. (The passenger seat doesn't.) When all the bolts are off, lift up the seat and disconnect its plug from underneath.
You'll want to use the claw hammer to pry off the socket and wire from the seat's underside, too. It's secured by a sturdy clip. You'll be taking out the seat belt buckle later on.
The seat is now ready for removal. You'll need some muscle to move the seats (I suggest getting a friend to help you). When the seat is removed, have it lie on its side so that the "inboard side" (i.e. the one closest to the handbrake) is exposed.
The next few steps will deal with the seat belt buckle removal.
To remove the seat belt buckle, you'll have to remove the inboard side cover. Look within the upderside of the seat and inboard side cover. You'll see this round clip that keeps the inboard side cover in place and prevents its removal. Use your prying tools (pliers, screwdriver, claw hammer) to get it out.
The wire for the seat belt sensor has another clip on the side of the seat. Remove this with your prying tools - again, the claw hammer works wonders here.
With the clips removed, you can pop off the inboard side cover to get to the seat belt buckle. It's connected to the seat via another clip, this time made of metal, but it's just there to snap the cover in place.
Ready your trusty 14mm socket wrench again. You'll need it to remove the seat belt buckle's anchor bolt. Note that it has a number of washers, some of them spring while the others flat and/or locking. Make sure not to lose any of them. Fasten them back to the seat for safekeeping.
The Bride seat rails come with their own seat belt anchor bolts and washers, too. Again, don't lose any of them.
Seat belt buckle

Seat belt buckle with anchor bolt and washers

Bride seat anchor bolt and washers
Take the Bride seat belt anchor bolt and the seat belt buckle. Swap out the 14mm socket for a larger 18mm one for the Bride anchor bolt's nut. Then fasten the seat belt buckle to the little flange on the side of the seat rails. The rails should have an instruction manual - they'll tell you which washers go in what sequence between the bolt and the nut. No knowledge of Japanese required.
The anchor bolt itself can be tightened with a 22mm socket.
Now that the seat belt buckle has been mounted to the seat rails, we need to mate the seat to its new feet. Take your 10mm socket wrench. I used a slim one with a T-bar end. You will use this to torque the 6x25mm bolts and mount the seat to the rails. (If you used M8x25mm button-cap bolts, you'll need a hex key or Allen wrench to torque those.)
Unlike Sparco and Bride which use four bolts to secure the seat to the rails, Recaro uses six. The front of the seat uses four of them already. You will need to slide the rails themselves backward to expose the holes for the bolts to fasten the seat to. Likewise, to fasten the rear end, slide the rails forward.
The instructions on the Bride rails would recommend you even use a spring washer and a flat washer per bolt. I couldn't get a hold of these at the size, so I went with just the bolts and torqued them down.
Once the rails have been mated to the seat, it's just a matter of bolting them to the Jazz's floorpan again using the 14mm seat mounting bolts from earlier. For the driver's seat, make sure you remember to plug in the seat belt sensor wire too.
When installing the seats to the floorpan, you might run into trouble lining up all the holes for the bolts. They may not line up perfectly. They may not look like they'll fit, but they will. Take your time and line up the holes one corner at a time, then use the mounting bolts as placeholders. Then torque them down.
Voila! Here's the result.