Single Member LLC

Are you the preparer? Did you llc him?

"How should he have ADP set him up?"

They don't. He doesn't need them, if he is the only person working for this business. He simply takes money whenever he wants to.

"ADP saying that a lot of customer have it st up this way."

They are wrong for the entity type of Sched C filing.

"he is wanting to pay himself"

As the owner of the Sched C business, all the money is his all the time and he takes a Draw (equity out) whenever he wants funds.

"and pay all the appropriate taxes like a w-2."

There is no W2 or 1099-M from his own business. He would need to estimate and pay Estimated taxes through the year, knowing how the business income contributes to his entire financial picture for 1040 purposes. Then, when you do the tax return, you also work up the Sched SE, which is the FICA taxes he is concerned about. That would compute how much he owed, along with the income tax liability, most of which should have already been paid as Estimates.

You posted this question in the Practice Advice section of the community forums. You also have a lot of topics along the same line, in Practice Advice. Practice Advice would be the forum section for you, running your own business, to be asking for guidance on business issues as you run your own business. For instance, are you taking tax preparation course meant for tax professionals? Continuing Education? Do you use the IRS publications and instructions for the answers you seek, before asking the peer users that volunteer here? This is not Tax preparation support. You seem to be leaning on other people that are as busy as you are, this time of year, for basic questions.