Remove battery - 2000 Buick LeSabre

Always remove the negative battery cable first. That will avoid the possibility of causing a spark trying to remove the positive first.
So you take a wrench and remove the negative post. If it is a sidepost battery, use an 8 mm wrench to remove the center bolt on the cable. If a top post battery, use the appropriate wrench to remove the negative cable terminal.
Now you can safely loosen and remove the positive battery connection.
Battery is now free to remove, but wait, there is a holding fixture on most batteries so it won't move around or tip over. Either a top bracket that hold battery stable, or there is a small little block at bottom of battery, like a wedge, to hold it secure. This block or wedge is retained by a small bolt, usually 1/2 inch size hex on the bolt (or 13 mm size, which is very close to 1/2 inch). remove this holding block or wedge and battery should come4 out. On some GM models there is a brace which is over the battery, and this brace must be removed for battery removal. Take one end of brace loose and swing it out of the way.

1. If equipped with power seats, move the seat to the most forward and upright position.
2. If equipped with manual seats, move the seat to the most forward position.
3. Turn the ignition switch to the Off position. Be certain that all electrical accessories are turned off.
4. Remove the battery cover (1).
5. Remove the negative battery cable (1) from the battery.
6. Disconnect the positive battery cable and position aside.
7. Remove battery thermal blanket.
8. 1. Remove the battery hold down retainers (2) and remove the battery hold down (1).
   WARNING: Wear a suitable pair of rubber gloves when removing a battery by hand. Safety glasses should also be worn. If the battery is cracked or leaking, the electrolyte can burn the skin and eyes.
   1. Remove the battery from the vehicle.
   
   

REMOVAL
1. Disconnect battery terminals
2. Remove bolt and battery clamp
3. Remove battery
4. Clean battery tray
5. If equipped with cruise control, disconnect multiplug and hose from cruise control vacuum pump.
6. Release harness clips from battery carrier
7. Remove 4 bolts and remove battery carrier.
8. Remove battery carrier and cruise control vacuum pump (if equipped).
9. Release starter motor solenoid terminal cover.
10. Remove nut securing battery lead to solenoid and disconnect battery lead
11. Disconnect Lucar connector from starter solenoid.
12. Remove 3 bolts securing starter motor to gear box. Note that the left hand bolt also secures the mounting bracket for the Crankshaft Position (CKP) sensor multiplug.
13. Maneuver and remove starter motor from vehicle.
INSTALLATION
1. Clean the starter motor mating face on the gear box.
2. Install the starter motor by reversing the procedure in the removal instructions.
3. Before connecting the battery, clean the cable terminals and the battery posts.
4. Apply a thin coat of petroleum jelly or dielectric grese to battery terminals after connecting.

Remove the negative cable end from the battery. Remove the positive cable end from the battery. Remove the hold down bolt from the front of the battery hold down. Loosen the rear battery hold down nut and remove the battery hold down. Remove the battery. Reverse this order to reinstall.

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

Below is the procedure for an Aston Martin Vantage, perhaps the vanquish is similar?

Removal
1. Power the driver's fully forward.
2. Remove rear compartment cover.
3. Loosen and disconnect battery terminals, earth (- ve)
terminal first.
4. Release rear carpet, studs (x2), move carpet aside.
5. Remove screws (x2), battery compartment cover to
support rail.
6. Remove nuts (x2), battery compartment cover to body.
Remove cover.
7. Remove Torx screws (x4), remove battery clamps (x2).
8. Disconnect battery vent tube.
9. With assistance, remove battery.
Installation
1. Clean battery tray and clamps.
2. With assistance, install battery into its compartment.
3. Connect battery vent tube.
4. Position battery clamps (x2), install and torque tighten
Torx screws (x4).
5. Ensure battery vent tube is not distorted by battery.
6. Install battery terminals, tighten terminal nuts to correct
torque.
7. Install battery compartment cover, install and tighten
screws (x2) and nuts (x2).
8. Position rear carpet, secure with studs.
9. Install rear compartment cover.
10. Reposition driver's seat.
Courtesy of pistonheads.com

Please vote if this helps! Thanks, Mike

One side of that battery will have a single 13 mm bolt that you can loosen and or remove entirely to allow you to remove that battery. Screws located down near the bottom of the battery.
The fender is on the left and then the battery and then the wedge is on the battery side which faces the engine. You need to remove it with a socket and long extension.

Remove the negative battery and place it out of the way then remove the positive cable and move it as well.Remove the heat guard or shield which surrounds the battery if installed.Remove the battery hold down wedge by unscrewing the bolt.Lift out the battery.Reverse for installation.--------------- Thank you.

Battery is behind the front left wheel. You have to remove the wheel to replace the battery. (you can access the battery w/out removing the wheel, but you can't actually get the battery out unless you take the wheel off.)

Once the wheel is off, remove the inner-fender well mud-guard and you will see the battery just forward of the wheel well. From there it's pretty straight forward.

Once this is removed, you should be able to see the battery hold-down bolts.

Remove these and remove the hold-down assembly.
If you are removing the battery, remove the 1st battery cable.

Depending upon what battery you have, you may be able to slide the battery back toward the wheel and disconnect the 2nd cable.

Jack the vehicle up, put on jack stands and remove the passenger side wheel.

On the front side of the wheel well there is an access panel that needs to be removed in order to access the battery. There are 6-8 1/4" screws to remove. Then manipulate the cover until you can remove it, bending it slightly.
If you were unable to disconnect the 2nd battery cable earlier, you can now move the battery further towards the rear of the car. Remove the 2nd cable clamp from under the hood.

Slide the battery all the way out. It is heavy!
Reverse the instructions for reassembly.

Hi!!

The battery is located in the fender, ahead of the right front tire. Te battery can be removed without reovint the tire, but removing it improves access.

Here is how to remove/replace the battery

Disconnect battery cables, negative first, then positive from remote terminals.

Remove air filter housing

Remove the two battery hold down clamp bolts and clamp.

Loosen right front tire lug nuts, rise the vehicle, support it w/jackstand and remove wheel.

Remove battery cover/splash shield from wheel well

Slide battery toward rear of vehicle and disconnect battery cables.

Remove old battery thru wheel opening and insert new one.

If helpful, click below

Removal Procedure

Disconnect the negative battery cable

Remove the wheelhouse liner.

Open the positive battery cable connection cover.

Loosen the positive battery cable bolt.

Remove the positive battery cable

Remove the front fender rear bracket to side rail bolts.

Remove the front fender to front fender rear bracket upper (1) and lower (2) bolts.

Remove the front fender rear bracket.

Remove the battery hold down retainer bolt and retainer.

Important: Do not tip the battery more than 40 degrees during removal.

Remove the battery.



Installation Procedure

Important: Do not tip the battery more than 40 degrees during battery installation.

Install the battery.


Install the battery hold down retainer and bolt.

Install the front fender rear bracket.

Install the front fender rear bracket to side rail bolts.

Install the front fender to front fender rear bracket upper (1) and lower (2) bolts.

Install the positive battery cable (1).

Tighten the positive battery cable bolt.

Close the positive battery cable connection cover.

Install the wheelhouse liner.

Connect the negative battery cable

The battery is located under the right front fender behind the tire. Remove the wheel, remove access panel from fender well. From engine compartment, remove 2 battery hold down bolts,10mm, slide battery rearward to remove battery cables.