How do i get the rear view mirror back on?

The rear WINDOW, or the rear view MIRROR?

The window can only be removed by an automotive glass place. You need special tool, glue and skills.

The rear view mirror is easier.

https://www.google.com/search?q=1999+lincoln+town+car+removal+rear+view+mirror

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Hi! Usually the wires are connected directly at the mirror which will require removal of the mirror trim or door panel

there is a small screw that holds the mirror to the window at the base of the rear view mirror arm.

This is slightly tricky, you need to pull out and completely clean the metal piece that the mirror attaches to. Go to the auto parts store and get a rear view mirror install kit, follow the directions EXACTLY. There is usually a primer and then a small amount of glue. nothing else works.

there is a separate motor for up/down and another for left/right adjust. The glass is serviceable but not the motors, built into the frame of the mirror body.

SECTION 501-09: Rear View Mirrors 2000 F-Super Duty/Excursion/Motorhome Chassis Workshop Manual
REMOVAL AND INSTALLATION Exterior Mirror Glass Removal
NOTE: Left-hand dual arm mirror with heat shown, non-heated and aero mirrors similar.

1. Position the exterior rear view mirror glass in the full down position.

1. Grasp the top and carefully pull the mirror glass away from the mirror housing.

1. Disconnect the electrical terminals (if equipped) and remove the exterior rear view mirror glass.

Installation

1. Remove the jack pins from the mirror glass back.

1. Remove the sealing boots.

1. Install the jack pins in the sealing boots.

1. Install the jack pins and sealing boots.
   1. Install the jack pins in the mirror housing.
   1. Install the sealing boots so the boot shoulder is under the mirror collar.

1. Loosely install the glass.
   1. Connect the electrical wiring to the electrical terminals (if equipped).
   1. Position the friction pins in the mirror housing.
   1. Align the jack pin locating tabs to match with the mirror glass back.

1. Using a flat hand, press on the center of the mirror glass until seated on the center pivot of the mirror housing.
   • Press the mirror glass toward one of the jack pins until snapped in place.
   • Repeat for second jack pin.

f

Replacing the rear view mirror on a Ford Explorer is easy. The only obstacle you might encounter is fear of breaking the glued metal plate off the windshield. Do not sweat it. You can buy glues at the auto parts store to reattach the mirror to the windshield (Difficulty: Moderately Easy).

Instructions:

1. Tap gently at the base of the mirror where it slides on over the metal plate glued to the windshield and pull upward. Some rear view mirrors have a small Allen screw that tightens the base of the rear view mirror to the metal plate. Disconnect the electrical plugs if your rear view mirror has them.
2. Pull the rear view mirror clear of the metal plate. Clean around the metal plate glued to the windshield. If the metal plate has come off because of harsh weather or from hammering too hard at it, reattach it with glue designed for this job.
   
3. Clean the area where you will be attaching the metal plate on the windshield. Apply the glue evenly on the surface of the metal plate that will go against the window. Be sure to clean and scrape off all the old glue before applying the new glue. Gently push the metal plate against the windshield in the spot you wanted it and hold tight for five minutes.
   
4. Wait a day before putting the base of the mirror or replacement rear view mirror onto the metal plate. Do not force the base over the plate. Forcing it will likely dislodge it again. Press firmly until it will not slide along the grooves of the metal plate. Reconnect your electrical plugs and tighten the Allen screw if your new mirror has one. Adjust the mirror according to your safe viewing preference
   

Hope help with this (remember rated this help). Good luck.

dealership for a $ or a local junkyard and swap out the guts

Order from the dealer the kit, you are right no epoxy will hold the mirror on.

are you trting to tighten the mirror glass or the mirror where it attaches to the body? I don't think glass is removable in 99. Only can try to press on glass to seat if unseated. not too hard.

1. Remove the front door trim panel; refer to Section 501-05 .
2. go to car-part.com for a used mirror. Page with * is cheapest seller.

1. Remove the speaker.
   1. Remove the screws.
   1. Disconnect the electrical connector.
   1. Remove the speaker.

1. Remove the outside rear view mirror (17682).
   1. Disconnect the power mirror wiring clips.
   1. Remove the outside rear view mirror nuts.
   1. Remove the outside rear view mirror.
      • Feed the power mirror wiring through the opening in the front door (20124).

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SECTION 501-09: Rear View Mirrors 2001 Explorer/Mountaineer Workshop Manual
REMOVAL AND INSTALLATION Exterior Mirror Glass, 2001 model Removal
NOTE: Exterior mirror glass is serviceable only on vehicles built after July of 2001.
NOTE: Passenger side exterior mirror shown, driver side exterior mirror similar.
All mirrors

1. Position the glass in the full up position.

1. Locate the notch at the bottom of the exterior mirror glass.

1. Release the exterior mirror glass.
   1. Insert a long flat-bladed screwdriver in the notch.
   1. Push the screwdriver into the notch until the glass is released.

Heated mirrors

1. Position aside the exterior mirror glass.

1. Disconnect the electrical connectors.

All mirrors

1. Remove the exterior mirror glass (17K707) passenger side or (17T675) driver side.

Installation
Heated mirrors

1. Connect the electrical connectors.

All mirrors

1. Position the exterior mirror glass on the exterior mirror motor.

1. Place a hand against the back of the exterior mirror housing and a hand flat against the exterior mirror glass. Press the glass in place until fully seated.

prop it up with broom