I found an instruction sheet for the replacement model (53867) of the access pad I currently own. The instructions worked perfectly and the code is reset. PLEASE NOTE: If the pad is currently installed, two people are required to reset the access code.
The instructions are as follows:
1. Lift the cover to access the keypad. Decide on a 4-digit code using numbers from 0 to 9. You can use a number more than once (for example, 4, 0, 4, 1)
2. Press the selected code digits on the keypad; THEN PRESS AND HOLD THE ENTER BUTTON, and press the SRT button on the Garage Door Opener end panel (Note, you need the second person to press the SRT button).
3. Depending on your opener model, when you press the SRT button either the opener light(s) will flash or the garage door will begin to move. Release the ENTER button.
Hopefully, this will save some people time searching on the internet.