In this instructable, I will share the simple process of removing the back seats on an RX300. My kids are still very young and believe me, things get spilled. To help eliminate odor and just to feel better about the general condition, sometimes its nice to actually clean under the seats. A spilled strawberry smoothie was cause for this exercise in my case.
Before you begin, please note that the passenger side seat is probably 60lbs and may require assistance to actually remove it. You may be able to tip and leverage it into the cargo area without as much effort, but be careful not to hurt yourself. As usual, proceed at your own risk. You will also need a size 14mm socket for the removal of the primary bolts. I used an impact wrench to get them loose as I could not get good leverage with my hand tools. I'm sure if I didn't have an impact wrench at my disposal I would have gotten them, but I would have had to break a sweat. :)
Also Note: You will need a size 10mm wrench and I recommend two standard flat head screw drivers to help remove the nylon push in clips.
Step 1: Where Do I Start?
For an easier process, remove any extras from the cargo area. Next, flip the seats forward so that you can gently pry the cargo floor cover up. In the photo above, I have already done this. There is no good way to display it, but seeing the finished result should help you visualize what has to happen.
After the cargo floor cover flap is flipped out of the way, you will see about 7 black circles along the edge at the back of the seats. These are the heads of the push-in clips holding the back of the seat covers. These will have to be removed carefully.
Step 2: Hidden Support Strap
With the push-in clips removed, you should now slide the seats all the way forward. This is done by sitting in the seat and pulling up on the control bar under the seat - you find it by reaching down past your knees and under the seat. While pulling up on the control bar, slide forward bringing the seat with you. You may be able to do this without sitting in the seat, but it will require more upper body strength.
Now, returning to the cargo area, you can flip the back cover up and see the hidden strap shown in the photo. There is a #10mm bolt holding this strap and you will need to remove it.
Step 3: 4 Primary Bolts
With the previous steps done, this will probably be self evident. See the photos for the bolts that are now accessible.
Step 4: Carefully Remove - Dont Hurt Your Back -
There are two bolts at the front of the seats, on the forward ends of the seat rails. These are underneath a snap on cover.
What I can tell you about the snap on cover is this - Spread the back "legs" and tip upward, then slide the cover toward the front of the car. This should avoid damaging the cover. Keep in mind these get brittle with age and may not snap back on. A small dab of silicon or other flexible adhesive will work well to keep the cover on if the clips break.
With all four primary bolts removed, you can remove the seats. Sorry I didn't get a photo for this.
Step 5: Access to the Mess
Now you can clean up whatever it is. :) Reverse the process to put the seats back in. Please ensure the 4 primary bolts are nice and tight, this is a real safety issue if they are not good and tight.
Good luck with the mess.