seat removal/ grounding

first off i need to know how to remove a rear seat in a 92 grand marquis

second, can you ground two amps by grounding one then running a ground from the second amp into the first amp's ground terminal?

thanks

I am not 100% sure about your seat removal, but I would try kneeling in front of the rear seat with your foot up against the back of the front seat and pushing the bottom of the rear seat toward the rear of the vehicle.  This should release the lock on that side and allow you to lift the seat straight up.  There are 2 locking tabs, one on each side of the seat.  If you were to sit on the back seat the lock would be directly under the area between your knees.

Your amps ground connection is made to handle the current of that amp alone.  You should run a dedicated ground wire per amplifier.  If it accepts a 4 Ga. wire, use one.