How to remove bottom of back seat need to remove seat to remove rear shocks..

Check in the trunk near to the back seat backrest and the carpet may cover it. There may be plugs over the access holes also.

What type of vehicle? Most rear seats you push down and back on front edge to unlock the clip that holds seat in place, but some have bolts along front edge.

If you have Air shocks in the back they are worn out

Your going to get that low ride when people sit in the
back even with new rear shocks & a small adjustment to
the level control to raise the rear

You need to air your tires to the max on tire sidewall

find bolts under the front of the seat itself. remove this seat and you will see 2 more bolts at the base of the back of seat part. remove these and normally the back part lift off some retaining clips. Replace in reverse order

hi you need to remove back seat and maybe the back seatbelt brackets on each side as they can get in the way then you can get to the 3bolts that hold the top of each shock in with a small socket or angled spanner

REMOVAL & INSTALLATION 1983-86 Models

1. On 4-door sedan, remove the package tray and vent duct.
2. On hatchback, remove the speaker grilles.
3. Disconnect the brake line from the wheel cylinder. CAUTION
   Brake fluid contains polyglycol ethers and polyglycols. Avoid contact with the eyes and wash your hands thoroughly after handling brake fluid. If you do get brake fluid in your eyes, flush your eyes with clean, running water for 15 minutes. If eye irritation persists, or if you have taken brake fluid internally, IMMEDIATELY seek medical assistance.
   
4. Remove the brake line from the brake hose.
5. Disconnect the brake hose from its bracket on the shock absorber.
6. Loosen, but do not remove, the nut holding the suspension support to the shock absorber.
7. Unbolt the shock absorber from the rear arm.
8. Unbolt and extract the shock absorber from the body. To install:
   
9. Attach the shock absorber to the body and tighten the 3 nuts to 17 ft. lbs. (25 Nm).
10. Engage the shock absorber bracket with the carrier and install the hardware. Tighten the nuts to 119 ft. lbs. (162 Nm).
11. Tighten the center suspension support nut to 36 ft. lbs. (49 Nm). There is a bearing located under the suspension support dust cover. Remove the dust cover and pack the bearing with multi-purpose grease. Once packed, reinstall the dust cover.
12. The remainder of installation is the reverse of removal. Tighten each component to specifications.
13. Have the rear wheel alignment checked.

1987-88 Models

1. On wagon models, remove the toneau cover holder.
2. Loosen the rear wheel lug nuts, raise the rear of the vehicle and support it safely. Block the front wheels.
3. Remove the rear wheels.
4. Using the proper size flare nut wrench, disconnect the backing plate hardware.
5. With a flare nut and a back-up wrench, disconnect the brake tube from the brake hose and use a small plastic container to collect the brake fluid.
6. Undo the clip and disconnect the brake hose from the shock absorber. NOTE: Before the axle bolts are removed, the axle carrier must be supported with a jack.
   
7. Support the axle carrier with a floor jack and remove the mounting bolts and nut. Disconnect the axle carrier from the shock absorber.
8. Support the shock absorber firmly by hand and remove the three mounting nuts. Remove the shock absorber from the body. To install:
   
9. Position the shock absorber onto the body and support it firmly by hand. Install the three nuts and tighten them to 23 ft. lbs. (31 Nm).
10. Attach the axle carrier to the shock absorber with the nuts and bolts. Tighten the nuts to 166 ft. lbs. (226 Nm).
11. The remainder of installation is the reverse of removal. Tighten each component to specifications.
12. Bleed the brake lines as described in Section 9.
13. Have the rear wheel alignment checked.

1989-96 Models

1. On the 4-door sedan, remove the package tray and vent duct. On 1992-96 models, it will be necessary to remove the rear seat back.
2. On the hatchback, remove the speaker grilles.
3. On the wagon models remove the tonnue cover and rear seat back.
4. Loosen the rear wheel lug nuts, raise the rear of the vehicle and support it safely. Block the front wheels.
5. Remove the rear wheels.
6. Disconnect the brake hose and the ABS speed sensor from the shock absorber.
7. If equipped with ABS, disconnect the Load Sensing Proportioning Valve (LSPV) spring from the lower arm.
8. Disconnect the stabilizer bar link from the shock absorber.
9. Support the rear axle and loosen the 2 bolts from the lower end of the shock absorber.
10. From inside the vehicle, unbolt the upper support. Fig. 1: A rubber cap covers the rear shock absorber tower nut
    Fig. 2: The upper shock absorber tower is retained by the center nut (circled) and three surrounding nuts
    
    
11. Lower the rear axle carrier and remove the two bolts.
12. Remove the shock absorber from the vehicle. To install:
    
13. Install the shock absorber assembly onto the vehicle.
14. Connect the brake hose and the ABS speed sensor to the shock absorber.
15. Connect the stabilizer bar link to the shock absorber.
16. Install the wheel and tire assembly.
17. During installation, please observe the following tighten specifications:
    1. Tighten the shock absorber-to-body bolts to 29 ft. lbs. (39 Nm).
    2. Tighten the shock absorber-to-axle carrier nuts to 166 ft. lbs. (226 Nm) on 1988-91 vehicles and 188 ft. lbs. (255 Nm) on 1992-96 vehicles.
    3. Tighten the suspension support-to-shock absorber nut to 36 ft. lbs. (49 Nm) on 1988-91 vehicles. On 1992-96 models, tighten the stabilizer bar link to shock absorber retainers to 47 ft. lbs. (64 Nm).
18. Install the rear seat back, vent duct and the package tray as required.

You will need to remove the rear seats to access the hole just above the shock. Remove the bottom seat cushion first, then find the small bolts that hold the upper seat to the frame. Once removed, you will see access to the top of the shocks (might have a plastic covering the hole).

sounds like the rear springs are weak replacing them will be the only fix

Answer
REMOVAL - SHOCK ASSEMBLY
NOTE: Access for the nuts attaching the rear shock assembly upper mount to the vehicle is through the inside of the trunk.

Roll back carpeting on top of the rear shock tower to access shock mounting nuts.
Remove plastic cover from the top of the shock assembly.
Remove 2 nuts attaching the shock assembly upper mount/spring seat to the shock tower.
Raise vehicle on jackstands or centered on a frame contact type hoist. (Refer to LUBRICATION & MAINTENANCE/HOISTING - STANDARD PROCEDURE)
Remove the rear wheel and tire assembly from the vehicle.
Remove two fasteners holding the splash shield to the shock assembly upper mount.
Remove bolt attaching shock absorber to rear knuckle (Shock Absorber Attachment To Knuckle).
Remove the shock absorber from the rear knuckle first when removing the shock absorber from vehicle by pushing down on the rear suspension.
Move shock assembly downward and tilt top of shock outward, then remove shock assembly from vehicle through top of wheel opening

if you bounce the car by putting your weight on the rear bumper with your knee you can test the rear shocks. If the car bounces more than once on the way up you need shocks. I generally replace shocks on new cars with factory installed shocks anywhere from 40,000 - 50,000 miles. There are bolts at the top and bottom of the shocks that will have to be removed. You can do this a little easier by removing the rear wheels and placing the car on Jack Stands.