I want to remove back seat is there a part to buy for where the seat is removed from

You have a broken wire in the seat. The blue wire inside the seat cushion will break or burn in two. If you are handy with tools you can remove the seat, remove the screws from the control switches cut the hog nose ring clips, undo the velcro on the back of the seat bottom and carefully remove the bottom seat cover. You will find that the blue heating element blue wire in burned in two. Cut the bad part out, slide some heat shrink tape over one end. Slide it far enough so that you wont shrink it from the solder gun. Solder the two wires together and keep the joint minimal so that the shrink tape will slide over the solder joint. shrink the tape with a heat gun or hair dryer.Put everything back in reverse order. You will need to go to an older conventional auto parts store and buy a hog nose ring kit with the pliars to replace the upholstery. Go to an upholstery shop and they can tell you where to buy it . It should cost 3 or 4 dollars. this whole seat repair should not cost over $8.00. Also remember check the fuses first and also remember that the seatbelt has to be fastened for the seat heater to work.

some cars yes..some no. I would go buy some 3M spray adhesive and glue it back. Unless you are really concerned about the looks. Then you would need to buy a new headliner and replace the old one. That can mean removing all door trim around the every entry, removing the rear deck lid, removing the rear seat back, removing anything that touches the headliner.

there are usually 2 little buttons, 1 on each side, underneath the seat in the front. push and pull up

Remove the seat cushion retaining bolts, detach the seat cushion and remove it up and out from the vehicle.

Remove the rear seat back retaining bolts at the bottom of the seat back. Pull up then out to disengage the upper frame from the hangers and remove seat back from the vehicle.

Installation is the reverse of removal.

Courtesy: Haynes GM repair Manual #38025. You can probably find a copy of it on Amazon or eBay cheap

PUSH IN CENTER FRONT EDGE CUSHION TO DISENGAGE PART OF SEATS WIRE FRAME FROM CLIPS.WITH CLIPS UNHOOKED LIFT UP AND REMOVE SEAT.IF REAR SEAT NOT HELD IN PLACE WITH CLIPS. LIFT UP THE REAR SEAT CUSHION AND PIVOT IT FORWARD. DETACH THE RETAINING BOLTS AT THE LOWER EDGE OF THE SEAT BACK AND IF NECESSARY REMOVE THE SEAT BELT ANCHOR BOLTS.LIFT UP ON SEAT BACK REMOVE IT..

I searched the owner's manual and there was no mention of folding the rear seats down. If you don't have a manual, you can get one here: http://www.extendedgmwarranty.com/owners-manual/buick/1999-Buick-Century.pdf

You can remove the seats following the instructions below from autozone.com.
Rear Seats
SEAT CUSHION

Fig. Typical W-Body rear seat cushion removal

1. Locate and remove the small bolts at the front lower edge of the seat cushion.
2. Pull the tabs on the rear cushion retainers.
3. Remove the seat cushion by lifting up and pulling out of the retainer.
4. Installation is the reverse of the removal procedure. Make sure the retainer tabs are snapped into place. Tighten the bolts to 18 ft. lbs. (25 Nm).

SEAT BACK

Fig. Typical W-Body rear seat back removal

1. Remove the seat cushion as described above.
2. Remove the anchor nuts securing the rear seat retainer at the bottom of the seat back.
3. Grasp the bottom of the seat back and swing upward to disengage the offsets on the upper frame bar from the hangers.
4. Lift the seat back upwards to remove from the vehicle.
5. Installation is the reverse of the removal process. Make sure the hooks on the seat back are properly installed to the hangers. Tighten the anchor nuts to 89 inch lbs. (10 Nm).

you must buy the hole blt they are not to be disasembled for safety reasons the belt should bolt under the rear seat

please rate highly if this is what you need

Section 01-10: Seats and Tracks 1994 Mustang. Workshop Manual
REMOVAL AND INSTALLATION Seat Cushion, Rear Removal and Installation

1. Release pin from locks by pressing release button under rear seat cushion.

1. Pull rear safety belt and buckle (60044) through openings in rear seat cushion pad and frame (600A88) and remove rear seat cushion pad and frame .

1. To install, reverse Removal procedure.
   

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Section 01-10: Seats and Tracks 1994 Mustang. Workshop Manual
REMOVAL AND INSTALLATION Seat Back, Rear Sedan
Removal

1. Remove rear seat cushion as outlined.

1. Remove rear seat bolster. Refer to Section 01-05 .

1. Remove rear seat bolster mounting bolts. Remove bolster assembly.
2. Remove four seat back to package tray retaining bolts.

1. Remove seat back.

1. To install, reverse Removal procedure.

it is not designed to be removed. It is designed to slide back and forth as needed.

Section 01-10: Seats and Tracks 1998 Villager Workshop Manual
REMOVAL AND INSTALLATION Seat, Rear Bench
Removal

1. Remove the center seat(s) if equipped. Refer to the procedure in this section.
   

1. Slide the bench seat forward to the center row seating position.
   

1. Use a flat-blade screwdriver to remove the cover caps from the front of the rear seat cushion latch cover.
   
   
   
   
   

1. Remove the two rear seat bolts from the front of the rear seat cushion latch cover.
   
   
   
   
   

1. Lift the rear seat cushion floor cover on the back of the rear bench seat and remove the two inboard rear seat bolts and the two outboard rear seat bolts.
   
   
   
   
   

1. Remove the bench seat from the vehicle through the body side door opening.
   

Hi Xit.....The factory XM module is in fact located under the rear shelf trim panel. You will have to remove the rear seat cushion, just pull up on the front of the cushion about 12 inches in from left and right corners. Remove the cushion from the car. Open the trunk and remove nuts located on the seat back just under rear shelf metal. Back inside the rear seat area, remove the seat belt buckle bolts located inboard of right and left lower corners of the seat back. Remove the seat back. You will now be able to see the (2) plastic fir tree pins that hold the shelf panel trim in place. Remove the pins.
Now comes the hard part, remove the right and left quarter sail interior trim panels ( Caution: roof rail air bag located behind right and left panels) the fasteners are located behind the "SIR" plastic buttons in the sail panel trim.
All in all, unless you have the proper tools and take the proper precautions, you might want to take your Cadillac to your local dealer.
Buy the way, is there something wrong with your factory XM module?
Let me know, regards.