Check out this old thread. I think it describes the procedure for your opener.

Was that the right link? That thread goes on forever, I feel like I have read most of them and can only find the hold the learn button or your gdo is fried buy a new one. The hold the button does not work.

I'm not sure, but near the beginning is:
Just purchased a home that has a Sears Craftsman 1/2 HP garage door opener model 139.53615SR mfg. 07/1991 and a wireless keyless entry on the door model Sears 41A3625 K711. I am trying to program the keyless entry and have not been able to figure it out. We are still using the former owners program. Can anyone help me?

and: On the back of the motor unit near where all those white wires go you will find a button. Press and immediately release that and then walk over to your keypad and enter a four digit code of your choice and press enter. You should be good to go.

On the side of the learn button there is a light. Push and hold the learn button in until that light goes out and that is going to erase all the memory in that opener. Nothing will work with it until you reprogram everything back to it. When you erase the memory you always hold the button until the light goes out when you reprogram something you push it and immediately release it then you have 30 seconds to program what ever it is your trying to program to it.