The instruction might be on a label on the opener itself or possibly under the keypad cover. If not you can find them in your owner's manual. You can view the manual online at Manage My Home using the model number and the instructions in the link below. The model number will be on the overhead opener and should start with a "139" prefix.
Programming can vary on some models, but for any newer Craftsman openers that have a "learn" or "smart" or "SRT" button on the overhead opener, the instructions in the additional links below will also work for programming.