You get tools and you take it out or if you dont know how to take them out go to an engineer
unscrew the bolts and take the seat out
Remove rear seat and remove battery
Push very hard at the center of each back seat (left and right seat) towards the back of the car. Then, while pushing back, lift up. It will pop out of its catch.
remove passenger seat in 2003 cadillac cts
2000 sonata rear seat removal
Unbolt it from the floor
Its under the rear back seat, you need to remove the bottom portion of the rear seat to get to it.
Photos of tabs to remove
1. Remove bottom part of back seat 2. Unscrew back seat back bolts to remove upper back part of seat 3. Once you do this you can get right at the speakers by removing the cover on top of the speakers
Grab it from underneath the front of the back seat and exert a little pressure to jerk it up. It won't hurt the seat. The battery is located under the back seat. The seat goes back with no problem.
I have a 2000 Deville DTS. The battery is located below the back seat. Just pull up the seat (not back), and you will find the battery.
Look under your back seat. I have a 2001 Seville and that is where mine is located. The seat pops out very easily.