How do I remove a fuel tank from a 2004 Buick Rendezvous

First of all, there is a recall for gas tank replacement for your vehicle. The dealer will replace it free. The link will get you to the document in PDF form
Redirect Notice
It looks like there is a bracket on one end of the tank hidden by a heat shield

FUEL SUPPLY SYSTEM Fits Buick Rendezvous

What follows are two sets of instructions based on your V.I.N.
**Fuel Tank Replacement Prior to VIN 4S558922
(100mm Sender)********************************
Removal Procedure
Important
Always maintain cleanliness when servicing fuel system components.
1. Relieve the fuel system fuel pressure. Refer to Fuel Pressure Relief Procedure .
2. Drain the fuel tank. Refer to Fuel Tank Draining Procedure .
3. Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
4. Disconnect the fuel tank wiring harness connector at the body pass through.
5. Disconnect the quick-connect fitting at the inlet side of the in-pipe fuel filter
6. Disconnect the quick-connect fitting on the fuel return pipe, near the fuel filter.
7. Disconnect the fuel tank evaporative emission (EVAP) pipe quick-connect fitting near the fuel
filter.
8. Remove the fuel feed, the fuel return, and the EVAP lines from the fuel pipe retainer.
9. Remove the retaining nut for the EVAP canister bracket.
10. Loosen the fuel tank filler pipe hose clamp.
11. Disconnect the fuel tank filler pipe from the fuel tank.
Notice
Do not bend the fuel tank straps. Bending the fuel tank straps may damage the straps.
12. With the aid of an assistant, support the fuel tank and remove the fuel tank strap attaching bolts.
13. Remove the fuel tank from the vehicle and place the fuel tank in a suitable work area.
14. If the fuel tank is not being replaced, go to the Installation Procedure.
15. Disconnect the fuel tank wiring harness from the fuel sender assembly.
16. Remove the fuel sender shield from the fuel tank.
17. Disconnect the fuel feed and return pipe quick-connect fittings at the fuel sender.
18. Disconnect the EVAP vapor pipe assembly from the fuel sender.
19. Remove the fuel and/or EVAP pipe assembly from the fuel tank.
20. Remove the fuel sender assembly.
21. Remove the EVAP vent solenoid valve.
22. Remove the EVAP canister.

Installation Procedure
1. Install the EVAP canister (3). Refer to Evaporative Emission (EVAP) Canister Replacement .
2. Install the EVAP vent solenoid valve (2). Refer to Evaporative Emission (EVAP) Canister Vent
Solenoid Valve Replacement .
3. Install the fuel sender assembly (1). Refer to Fuel Sender Assembly Replacement .
4. Install the fuel and/or EVAP pipe assembly.
5. Connect the EVAP vapor pipe to the fuel sender assembly.
6. Connect the fuel feed and fuel return pipes at the fuel sender. Refer to Quick Connect Fitting(s)
Service (Plastic Collar) .
Notice
Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These
coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage
to parts and systems.
7. Install the fuel sender shield to the fuel tank. Tighten
Tighten the shield nuts to 6 N·m (53 lb in).
8. Connect the fuel tank wiring harness to the fuel sender assembly.
9. With the aid of an assistant, position and support the fuel tank.
Do not bend the fuel tank straps. Bending the fuel tank straps may damage the straps.
10. Install the fuel tank retaining strap attaching bolts (2). Tighten
Tighten the fuel tank retaining strap bolts to 47 N·m (35 lb ft).
11. Install the EVAP canister retaining nut. Tighten
Tighten the EVAP canister retaining nut to 6 N·m (53 lb in).
12. Connect the fuel tank filler pipe (2) to the fuel tank (1). Tighten
Tighten the fuel tank filler pipe hose clamp to 2.5 N·m (22 lb in).
13. Connect the fuel feed pipe quick-connect fitting (1) at the inlet side of the fuel filter. Refer to
Quick Connect Fitting(s) Service (Plastic Collar) .
14. Connect the fuel return pipe quick-connect fitting near the fuel filter. Refer to Quick Connect
Fitting(s) Service (Plastic Collar) .
15. Connect the fuel tank EVAP pipe quick-connect fitting near the fuel filter.
16. Connect the fuel tank wiring harness connector (1) at the body pass-through.
17. Lower the vehicle.
18. Add fuel and reinstall the fuel tank filler pipe cap.
19. Connect the negative battery cable.
20. Inspect for fuel leaks with the following procedure:
A. Turn ON the ignition for 2 seconds.
B. Turn OFF the ignition for 10 seconds.
C. Turn ON the ignition.
D. Inspect for fuel leaks.


*****************Fuel Tank Replacement VIN 4S558922 and Later (130mm Sender)************************************************

Removal Procedure
Important
Always maintain cleanliness when servicing fuel system components.
1. Relieve the fuel system fuel pressure. Refer to Fuel Pressure Relief Procedure .
2. Drain the fuel tank. Refer to Fuel Tank Draining Procedure .
3. Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
4. Disconnect the fuel tank wiring harness connector (1).
5. Disconnect the fuel pipes. Refer to Quick Connect Fitting(s) Service (Plastic Collar) .
6. Remove the EVAP canister bracket nut.
7. Loosen the fuel tank fill pipe hose clamp.
8. Disconnect the fuel tank fill pipe (2) from the fuel tank (1).
9. Disconnect the EVAP vent pipe near the fill pipe hose. Refer to Quick Connect Fitting(s) Service
(Plastic Collar) .
10. With the aid of an assistant or a transmission jack, support the fuel tank and remove the fuel tank
strap attaching bolts (2).
11. Remove the fuel tank from the vehicle and place the fuel tank in a suitable work area.
12. If the fuel tank is being replaced, perform the following steps:
A. Remove the fuel sender (1). Refer to Fuel Sender Assembly Replacement .
B. Remove the fuel tank wiring harness from the fuel tank.
C. Remove the fuel pipes from the fuel tank.
D. Remove the EVAP vent solenoid valve (2). Refer to Evaporative Emission (EVAP)
Canister Vent Solenoid Valve Replacement .
E. Remove the EVAP canister.

Installation Procedure

1. Install the EVAP canister (3). Refer to Evaporative Emission (EVAP) Canister Replacement .
2. Install the EVAP vent solenoid valve (2). Refer to Evaporative Emission (EVAP) Canister Vent
Solenoid Valve Replacement .
3. Install the fuel pipes to the fuel tank.
4. Install the fuel tank wiring harness to the fuel tank.
5. Install the fuel sender (1). Refer to Fuel Sender Assembly Replacement .
6. With the aid of an assistant or a transmission jack, position and support the fuel tank.
7. Install the fuel tank strap bolts (2). Tighten
Tighten the fuel tank strap bolts to 47 N·m (35 lb ft).
8. Install the EVAP canister bracket nut. Tighten
Tighten the EVAP canister bracket nut to 6 N·m (53 lb in).
9. Install the EVAP vent pipe near the fill pipe hose.
10. Install the fuel tank filler pipe hose (2) to the fuel tank (1). Tighten
Tighten the fuel tank filler pipe hose clamp to 2.5 N·m (22 lb in).
11. Connect the fuel pipes. Refer to Quick Connect Fitting(s) Service (Plastic Collar) .
12. Install the fuel tank wiring harness connector (1).
13. Lower the vehicle.
14. Add fuel as necessary and install the fuel tank filler pipe cap.
15. Inspect for fuel leaks. Perform the following steps:
A. Turn ON the ignition for 2 seconds.
B. Turn OFF the ignition for 10 seconds.
C. Turn ON the ignition.
D. Inspect for fuel leaks.