September 30: LEMON manuals is back up on a temporary server! Slowness is possible

Installation Procedure

Install the battery into the transmitter with the positive side of the battery facing up.
Use a type CR2032 battery, or equivalent.

Fig 1: Removing/Installing Transmitter Battery
Courtesy of GENERAL MOTORS CORP.
Snap the front and back half of the transmitter together.
Ensure the transmitter halves are tight to prevent moisture from intruding into the transmitter.