I have an older Sears garage door opener that works fine. I am in need of a new hand held remote to open the door from my car. The opener is a Sears Crafsman 1/3 HP model # 13953210. Serial #1481hoo812. It has a small opening on the back of the body of the opener that has a line of plastic switches that may have something to do with programing a new remote. What remote can I buy that will work with this opener and how will I program the new romote to this older garage door opener? Thank you for your help.