He can register an account at coinos.io in a couple of seconds and join hundreds of other merchants using it to take retail lightning payments. 

We'll get him listed on our homepage and btcmap.org and start promoting him to the community in an effort to send new business his way. 

Once he accumulates a bit of a balance it's easy to withdraw to an on-chain cold storage address at any time. We can walk him through options for setting that up when the time comes.

I'd suggest printing out a QR code linking customers to his profile page e.g. https://coinos.io/shawarmacorner and posting it up near the cash register. From there they'll be able to create and pay invoices and add tips all from their phone without him or his staff having to use a device to generate an invoice or QR for them to scan.

We tell merchants to just enter all bitcoin sales as "cash" into whatever existing PoS and accounting systems they already have in place. We report what the CAD value is at the time of sale and total up all payments for the day so they can easily see them all at cash out time.

If he already has a tablet or phone to receive payment confirmations, great, he can install the app on his homescreen. If not, we're happy to ship out one of our custom thermal receipt printers to provide even easier paper notifications. See this video for more info: https://www.youtube.com/watch?v=JiGoOJZUrP8&ab_channel=AdamSoltys