First remove your oem mirror. Twist it 1/3 of a turn (like turning a doorknob) in either direction to free it from the windshield mounting button.
I am told that some mirrors have a small connector in the stem that is covered by a plastic panel on the stem. If your mirror has this connector, remove the plastic panel ( prys up) and unplug the connector. Now you can work on the mirror at your workbench. If there is no connector, then separate the two halves of the mirror now to gain access to the receiver.
Most owners report that even though they tried several tools to pry the halves apart in an attempt to not mark the mirror's body, a small screwdriver worked best and did leave small marks. Keep in mind that you are not going to use this mirror again, so this is not a real concern.
There are 11 "snaps" which hold the two pieces together.
Most owners report that some of the tabs break while separating the halves..
When
you open the mirror, you will see the module itself, with the wires that come
from the mirror's base. You will have to disconnect the wires from it to remove
the module. There is a green or white plug with the colored wires attached to
it that run through the hole in the center of the mirror.
The photo below shows the wires out of the center hole, only because this photo
was taken after they were removed.
Carefully free the antenna, it is held in 4 or 5 places.
Push the clip away from the PC board and lift the PC board out.
Gently disconnect the connector.
+
Draw yourself
a diagram of the plug and the wires.
Verify that your wires are the same color.
If not, make a careful note describing your colors.
Using a sharp object, lightly press on the metal connector of each wire through its small opening in the white [green] plastic plug, and pull the wire off.
Gently pull wire out of connector.
Here's a close-up of a wire.
There's a little tab which held the wire in the connector.
Pressing the tab allows the wire to be pulled out.
Sometimes the tab stays pressed and you have to bend it back up a little so
that it will click back into place when it is inserted back into the connector.
Then pull the wires out through the mirror base. Now you need to use the diagram you drew to reconnect the wires with the module itself. At this point, you can reconnect the module to the car to make sure it still works (which it did, the procedure I'm describing is simpler than it sounds).

Pry the lamp cover off.
Although you pry from the left, when replacing the cover the left side goes
on first.
Remove bulb by pressing tab on right side of bulb.
I used gloves to not get fingerprints on the bulb.
Pry the lamp socket out
Pull socket all the way out
Remove the Torx-25 which is now exposed (Already done in photo)
Remove the two Torx-25 screws from each visor.
Remove the
windshield visors (you'll need a Torx driver to do that—size T25 bit). Then,
use a flat screwdriver to pry open the dome light cover. Remove the light bulb,
then pry the white plastic case of the light off. Underneath you'll find a screw
- remove it [Torx T25]. Now you can remove the plastic cover off the top of
the windshield. AT this point, find a place for the remote module, secure it
in place. Owners report using thin foam shipping material packed around the
module to hold it in place.
These instructions are compiled from owners help and photos. My 2000 ///M Roadster did not have keyless entry, so I do not have first hand knowledge of this operation. Any comments or instructions that you gain from performing this operation would be appreciated as I will add to this page to help other owners.