It's really easy, you get one of the terms booklets in the draw under the register and scan the top barcode before you hit total, it's going to go through stuff for the guest to enter in on the card reader, the first question is are they signing up for a debit or credit REDcard, if debit they need a voided check with them, credit they only need their license and social. You hit total and ask for their ID, you fill in their name and address while they fill in phone numbers, social security and PIN number, after you are both done ask the guest to verify the information you entered and once that is done it should say are they ready to submit their application. Once that's clicked it should print the receipt card with a barcode for before they get sent the card. or if they were not instantly accepted, it should print a small receipt saying they will be mailed for additional information. Then bam done signed up. Then you put that receipt into the booklet and give it to the guest and finish the transaction.
If they don't get accepted instantly, mostly happens with credit, they will need to use an alternative card to finish the transaction
If you need anymore clarification please ask because I don't know how good that comment was with the amount of sleep I have.