Moved in house 3 years ago, previous owners forgot password and do not have paperwork for the garage door or the keyless entry. Chamberlain model #4620 - house built Dec 1999-Jan 2000. Do you know how to reset it?

Make and serial number is all you need and proof you live at the house. Phone the company and they will confirm and give you info to reset. You will have your own pin no.

Here you go:
Sears Craftsman Liftmaster Chamberlain Garage Door Opener Battery Operated Keyless Entry Pads (http://www.chamberlain-garage-door-openers.com/keylessentry.htm)
Also has programming instructions.

Suggest go to this site.
Chamberlain garage door openers, gate openers, access control (http://www.chamberlain.com/corporate/en-us)

Click on Garage door openers;
Under Product Support, select instruction manuals;
Enter model number;

Chose 4620 model or 4620-2

Page 33 of instruction manual gives instructions for reseting codes.

Or go to this link directly, which is manual of 4620

http://www.chamberlain-diy.com/pdfdocs/A2167M.PDF

..

I have deleted a lot of this thread.

And giving you all a time out, everyone get into the corner till you can play nice.

And I would advice everyone to go to the FAQ and read the rules on the redies,

And since the question has been answered this thread is closed