After searching the forums, I found one thread about this from a decade ago with since-removed pictures. So here's a quick write-up! Let me know if I should add additional pictures. I rushed to take pictures as I went through the process.

You're still rocking your 2nd gen TL, either because you love it to death or it just won't die. Either way, after years of use and abuse, your seats might not look too hot with rips, tears, and scratches. The toughest part of this process is sourcing a seat, but if you hit enough junkyards, you'll find a good set. I went through 12 TLs in various yards and found one clean set of tan seats and two sets of black seats. So they're out there! Once you have your seats, the rest of this guide can help you.
Early TL seats -> Early TL = no problem
Late TL seats -> Late TL = no problem
Early TL seats -> Late TL = read this
Late TL seats -> Early TL = read this
The back seats are all designed the same, so if you find a nice one, it is only held on by one 12mm bolt near the driver side of the middle seat. The front is a different story. As you might find through either reading or attempting the swap yourself, not all front seats are the same. Earlier 2nd gen seats and later 2nd gen seats have different wiring due to the addition of a memory module. I believe the cutoff is 2001, so [1999, 2000, 2001] differ from [2002, 2003]. Someone correct me if I'm wrong about the years. You don't need to hack up the wiring though. Majority of the components are interchangeable. In fact, from what I've seen, everything is interchangeable except for the main harness and the seat rail motors. Hence this write-up.
This process isn't difficult. It takes about 30min if everything goes smoothly, and slightly longer if you run into wiring issues (which isn't likely but possible). For the front seats, you'll need:
-8mm (optional), 12mm, 14mm sockets or wrench
-Phillips head screwdriver

1. Here's what my seat looks like to start. Mine is a 2000, but the seat I sourced is from a 2003. As a result, the main harness plug is different.


2. Here is a look at what you are after. The upper and lower seat cushions are identical, including the wiring in each. You will have two connectors in the upper, two connectors in the lower.


3. To do this swap, you will keep your original base, but replace the upper and lower cushions and their associated wiring. It's completely plug-and-play. There are two full seats at the start, one that will donate a base and one that will donate cushions. I will call them BASE DONOR and CUSHION DONOR to differentiate.
a) Start by removing all of the plastic on both seats by taking out all of the phillips head screws. Then remove the lower cushion on both. The lower cushion is held on by 4 14mm bolts on either side of the base. Unplug any wires that prevent the cushion from being removed. (not pictured, it's easy)
b) Remove the upper of both seats. On the inner side (side closest to the center console), there is a motor for moving the backrest. Remove the 3 screws that secure it and remove the motor (phillips or 8mm, either works). Below that is a long 14mm bolt. Remove it. Further down is a 12mm bolt that will need to be removed. On the outer side (side closest to the door), there is one 12mm nut. Remove it. Unplug any wires that prevent the cushion from being removed. (pictured below)


4. Each base should look like this. Keep the wiring harnesses in each respective seat. The upper cushion and lower cushion from the cushion donor should each have two plugs.


5. At this point, you can swap any part from the cushion donor to the base donor. The following can be swapped and will be compatible for either seat type: headrest, plastic covers, seat control panel with switches, seat buckle, lower and upper cushion. You cannot swap the forward-backward motors on the seat rails, but you can swap the back adjustment motor. You cannot swap the memory module between seats. Start by attaching the upper seat cushion to the base donor. Secure it with the long 14mm bolt, the 12mm bolt, and the 12mm nut. Reattach the back rest motor.


6. Place the lower cushion onto the base and secure with the 4 14mm bolts. Reconnect the two wires from the upper cushion and two wires from the lower cushion. Reconnect any other wires that were disconnected during cushion removal.


7. Before you button everything back up, place the seat back in your car, hook up the control switches, and make sure everything works. You should make sure that all motors are working properly and none of the connectors are loose.


8. Reattach all of the plastic panels. Wait to put the headrest in until the seat is in the car. Underneath, make sure all of the cables are held out of the way of the seat rails. This can be done with zip ties or by bundling the wires under the cloth cover (as pictured). You will have two connectors hanging out, one yellow one for the airbag and one larger one for the main harness (blue connector for newer TL, gray connector for older TL).


9. Put the seat back in, verify that everything works, and send a picture of the finished product to someone who has been in your car before and commented about its condition. Congrats! You're done!


10. TROUBLESHOOTING TIPS:
-Backrest motor makes noise but won't move: the gear in the motor is likely not meshed properly with the backrest. Remove the motor, verify that it splines properly, then reattach. If problem persists, try the other motor.
-Seat rail motors aren't working: check your wiring. You might have plugged the wrong connector in or forgotten one altogether. If all wires check out, the motor might need replacing. Source one from another seat, or hack up the wiring from the cushion donor.
-No controls are working: try the other control switch panel to make sure the panel is good. Otherwise, verify all of the wires are properly connected

If you have any recommendations for revisions, please let me know. If you have any problems during the process, definitely post it. I only listed a few issues in the troubleshooting section so it would help to list additional problems. I don't know how many people this will help, but hey, might as well post it. Good luck!

 

^
write-up!
Try to find a decent salvage yard arm rest and resurrect the cushioning with the DIY below and the interior will be complete?

DIY: Flaccid Armrest Cushion Replacement - AcuraZine - Acura Enthusiast Community

There are pictures in the later pages.

 

so buying a used 07/08 Type S the transmissions are reliable?