How do I remove headliner on 2000 buick regal my sunroof won't close. checked switch it is not the switch.

No you don't need to remove the head liner to replace the switch . Here are the factory service repair manual directions .
Grasp the switch on the left and right sides. Use a small flat-bladed tool in order to disengage the clips which are located at the front and rear of the switch. Hold the flat-bladed tool parallel to the roof and push straight in. Rotate the switch toward the left side to disengage it from the mounting bracket and pull down. Disconnect the electrical connector from the switch. Remove the switch from the vehicle. This switch is supplied 5 volts from the sunroof module on the brown an orange wires ,the dark blue wire is grounded inside the sunroof module . The switch is just a low voltage input to the sunroof control module , The control module opens or closes the sunroof by the inputs from the switch . The odds the switch being bad are astronomical , more then likely the motor or the sunroof module are bad.
Your best bet would be to have a qualified repair shop diagnose the problem for you ! Do your power windows work ? Sun roof is powered by a circuit breaker an the windows are powered by the same circuit breaker .
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Important: This sunroof system is timed from the factory in order to allow the actuator to shut off automatically when the sunroof window reaches a certain position. Use extreme care when removing the actuator from the sunroof module. This may cause the timing to be thrown off. This may damage to the sunroof. Anytime the actuator needs to be removed from the module, ensure that the sunroof window is in the fully closed position.
Remove the sunroof window. Refer to Sunroof Glass Panel Replacement .
Slide the sunshade fully rearward. Move the sunroof window to the vent position. Remove the sunroof screws (two on each side). Remove the sunroof window from the module.
Place the sunroof module in the fully closed position. Remove the headliner. Refer to Headlining Trim Panel Replacement in Interior trim.
Tools Required ?€¢
J 38778 Door Trim Pad and Garnish Clip Remover

?€¢
J 2772-C Headliner Installer

1. Remove the sunshades. Refer to Sunshade Replacement .
2. Remove the overhead console, if equipped. Refer to Roof Console Replacement .
3. Remove the sunshade retainers. Refer to Sunshade Anchor Replacement .
4. Remove the power sunroof switch, if equipped. Refer to Sunroof Switch Replacement in Roof.
5. Remove the sunroof trim lace, if equipped. Refer to Sunroof Seal/Molding Replacement in Roof.
6. Remove the dome light, if equipped.
7. Remove the coat hooks. Refer to Coat Hook Replacement .
8. Remove the assist handles. Assist Strap Replacement
9. Remove the rail lamp. Refer to Roof Side Rail Lamp Replacement in Lighting.
10. Remove the windshield side garnish molding. Refer to Windshield Pillar Garnish Molding Replacement .
11. Remove the upper quarter trim panels. Refer to Rear Quarter Upper Trim Panel Replacement .
12. Remove the center pillar upper trim panel. Refer to Center Pillar Upper Trim Panel Replacement .
13. Pull down on the door opening weatherstrip seal on both the front and the rear doors.
14. Remove the 2 rear retainers (2) using J 38778 Door Trim Pad and Garnish Clip Remover. Disconnect the headliner electric harness at the right side of the rear window shelf. Rotate the right front seatback to a horizontal position. Remove the headliner from the vehicle through the right front door.
    

Disconnect the electrical connector from the actuator.
Important: Before removing the actuator, ensure that the pins J 41718 are tight and holding the cable.
Thread the J 41718 into the front sunroof window screw hole in order to retain the cable adjustment. Remove the sunroof actuator screws. Remove the sunroof actuator from the module. Did you look for a video on youtube ?

god morning check the rails if there is any thing blocking the sunroof way, or the motor of the sunroof might be broken. but mostly the problem is from the rails.

have a nice day

HAVE SAME PROBLEM ON MY ALERO , WOULD CLOSE TO VENT POSITION ALL OTHER FUNCTIONS WORKED FINE. TALKED TO A MECH. FRIEND AND FOUND A WAY TO CLOSE MANUALLY BUT YOU DO HAVE TO DROP FRONT LEFT CORNER OF HEADLINER.
THE MOTOR IS UNDER SUNVISOR AREA AND YOU'LL NEED AN ALLEN(SPELLING)SOCKET TO CLOSE ROOF

It can be faulty motor or loose wiring issue or faulty /weak sunroof controlling switch or there is some blockage for sunroof to come down to close or sunroof out of its track the headliner is out of its way.There re many possibilities.All this basics needs to be checked.For further troubleshooting,go through this help link:----
Click the link mentioned below:------
How to Manually Close the Sunroof ? http://howtobyme.blogspot.in/2012/05/how-to-manually-close-sunroof-on-2001.html

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Sunroof Stuck open? http://howtobyme.blogspot.in/2012/05/2001-lexus-is300-sunroof-stuck-open.html

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How to manually close Sunroof on Navigator? http://technoanswers.blogspot.com/2012/01/how-to-manually-close-sunroof-on-2000.html

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This will help.
Thanks.

check the fuses/ if ok check you are getting a 12v supply to the switch/also check the rails on the sunroof are clear of debri

This can be really tricky to get at if you want it done properly and neatly. You'd have to remove all the trim on the inside of the car that covers the headliner and then slowly pull the headliner down which will be held on by Velcro fasteners and some glue. You have to be gentle as the headliner may rip if you're too rough. Once the headliner is removed, you can get to the motor and cables. You'll be able to disconnect the cable connecting the sunroof and manually close it, and then re-secure the cable temporarily.

Have some one operate the switch while you tap on motor with hammer,this will jar the brushes and ussualy get back working temporarily.

The roof slides along a channel actuated by a coiled cord.

Both of the cords pass along a gear attached to the Sunroof motor which pulles the cord tooth by tooth.

There are two plastic wedges that drop into the plastic slides on the sunroof (the plastic slides are behind the more forward metal slides.)

The plastic slides control the tilt of the roof when moved independantly. The plastic wedges join them.

If the roof moves too far back, it is possible for the wedges to stick up and jam the roof open.

This should never happen, but could if the two micro switches on the sunroof motor assy fail to provide feedback to the controller indicating the roofs position.

Access to the Sunroof motor requires you to drop the headliner.

To drop the headliner, the plastic pillar shrouds need to be removed front and back, the seatbelt bolts in the middle secion need to be removed, the oh-**** handle, the front visors, and cabin lights.

3 bolts hold the motor up.

With the motor down you can try* to manually actuate the cords using a flat screwdriver, but move the left and right side evenly a tooth at a time.

Of course of the plastic wedges are jammed, it's not going to budge.

Hope the info is helpful. good luck!