Windshield pillar trim removal - 1998 Cadillac DeVille

The rear auxiliary heater and air conditioning control replacement procedure starts with removing the HVAC control assembly bezel (trim) from the headliner. Next, the headliner must be lowered in order to access the rear of the HVAC control assembly. This requires removal of the windshield garnish molding (A-pillar trim) and upper pillar garnish molding (B-pillar trim) at a minimum. You may be able to gain the necessary access by allowing the headliner to "hang" slightly rather than removing it entirely. After this is done, the electrical connectors can be disconnected and the HVAC control assembly can be removed from the headliner. You can read more here: https://www.yourmechanic.com/article/how-to-replace-an-ac-control-module-by-spencer-clayton

You have to remove every trim around :
1- Windshield,
2- Door pillar,
3- Back glass
4- Seat belt bolt at the center pillar.
5- Remove dome light.
To remove trim you have to pull (snap holding) careful not to break it.

Hope it helps.

I don't know about your Mitsubishi but generally windscreen trim is laid loose around the screen and theoretically can be reused. In practice the windscreen adhesive bead usually spreads and catches the trim in places effectively placing an element of doubt over the fact.
If a new trim isn't readily available or is prohibitively expensive, as long as care is taken to leave the visible part undamaged when cutting out the old screen or removing the trim the windscreen adhesive is so good it will bond even damaged trim and can be held securely.

One problem with reusing trim is when attempting to refit it will often be found to be too short. Contaminants from the atmosphere and UV exposure does tend to alter the properties of plastic. Once the trim has been removed shrinkage can sometimes be severe and rapid.

Windscreen water leaks should be none-existent with bonded screens but when windscreens must be replaced the fitters usually manage to scratch the paintwork in the screen recess and have no time or will to repaint. The adhesive bead rarely covers the exposed steel and as the trim is not designed to keep water out rust soon begins to attack and eventually destroys part of the windscreen bond and even sometimes eats through the steel into the windscreen pillar or roof.

1) Front End Sensor - Right--Located under the front hood in the engine compartment (2) I/P Air Bag--Located at the top right under the instrument panel (3) Roof Rail Air Bag - Right--Located under the headliner, extending from the passenger front windshield pillar to the passenger rear windshield pillar (4) Side Impact Sensor (SIS) - RF--Located under the right front door trim near the lower rear of the door frame (5) Sensing and Diagnostic Module (SDM)--Located underneath the vehicle carpet under the center console (6) Seat Belt Pretensioner - RF--Located under the trim near the bottom of the center pillar (7) Side Impact Sensor (SIS) - RR--Located under the right rear door trim near the lower rear of the door frame (8) Roof Rail Module - Right--Located behind the garnish molding on the upper rear pillar (9) Roof Rail Module - Left--Located behind garnish molding on the upper rear pillar (10) Side Impact Sensor (SIS) - LR--Located under the left rear door trim near the lower rear of the door frame (11) Seat Belt Pretensioner - LF--Located under the trim near the bottom of the center pillar (12) Side Impact Sensor (SIS) - LF--Located under the left front door trim near the lower rear of the door frame (13) Roof Rail Air Bag - Left--Located under the headliner, extending from the driver front windshield pillar to the driver rear windshield pillar (14) Steering Wheel Air Bag--Located on the steering wheel (15) Vehicle Battery--Located at the front left of the engine compartment. (16) Front End Sensor - Left--Located under the front hood in the engine compartment

YOU MEAN HOW TO REMOVE A PILLAR TRIM
pillar trim removal AudiWorld Forums


http://www.audiworld.com/forums/q5-sq5-discussion-129/pillar-trim-removal-2854535/

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 ?

I've had many a vehicle do that. If you have any trim around the windshield or up the pillars, it can get rust holes right through and you won't discover them until those trim pieces are removed

"A" pillar trim

You could replace the sensor or try disconnecting the DRL control module .What relay was replaced ? I see no relay on wiring diagrams or in service info. Replacing the Daytime Running Lamp (DRL) Ambient Light Sensor isn't hard . Just take the top dash pad off ,easy .
Removal Procedure
Remove the instrument panel (IP) upper trim. Refer to Instrument Panel Upper Trim Pad Replacement in Instrument Panel, Gages and Console.
Remove the security system LED. Refer to LED Indicator Replacement - Vehicle Security System in Theft Deterrent.
Twist the DRL sensor counterclockwise in order to remove the sensor from the IP upper trim.
Remove the DRL sensor from the wiring harness.

Removal Procedure
Remove the windshield garnish molding. Refer to Windshield Pillar Garnish Molding Replacement in Interior Trim.
Important: Remove the upper trim panel slowly, the retainer clips could possibly fall into the instrument panel.
Lift the instrument panel (IP) upper trim panel approximately 51 mm (2 in) and pull rearward to release the retainers.
Remove the DRL ambient light sensor. Refer to Daytime Running Lamp (DRL) Ambient Light Sensor Replacement in Lighting Systems.
If equipped, remove the sun load sensor.

Pull the windshield garnish molding from the A-pillar in order to disengage the retaining tabs and clips.
Remove the windshield garnish molding from the A-pillar.

Daytime Running Lamps (DRL) Control Module
Left side of the IP

Removal Procedure
Disconnect the battery negative cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
Remove the instrument panel insulator. Refer to Instrument Panel Insulator Panel Replacement - Left Side in Instrument Panel, Gages and Console.
Slide the daytime running lamp module from the bracket.
Disconnect the electrical connectors.

most likely when some one replaced the windshield they did not put the self sealing riviets in that hold the trim on. remove the cover on the side of the windshield and look. if that is not it check the moon roof drain tube runs in the a pillar