Have chamberlain security plus 950cb lost instructions.

Http://www.chamberlain-diy.com/doityourself/pdfdocs/114A2184.pdf
This web address came from the Chamberlain site. I also needed to relearn my remotes due to a newer car that has a built in garage door opener that needed to be set. I also needed to reset my keypad remote, those instructions I was able to get from the same site. Good Luck

Put a new battery in the 950 CB clicker and then climb up a ladder towards the garage opener. Press the orange LEARN BUTTON on the back of the opener. The light above the button will stay on. Position your clicker next to the LEARN BUTTON and press it ,the light on the garage opener will blink twice. Once the light stops blinking, press your clicker the garage door should start lifting. On the wall mounted unit after installing a new battery if it does not function after you enter your 4-digit PIN then you will have to dismount it from the wall and climb up the ladder and do the same steps as you did for the clicker. Since I didn't have a manual for either unit and my model numbers wouldn't come up on the Chamberlain.com site. I called their 1-800-528-5880 number and was told that my model numbers were obsolete. The 950 CB clicker is now 953 EV and the Chamberlain 1/2 HP model 7320 garage opener manufacturer date 11/01 wall mount is 945 CB.

Contacted Chamberlain free of charge