Doesn't sound like he's published yet. If he were he'd probably have a publisher to handle this kinda stuff.
This day and age the best option might be so self publish as an ebook which is fairly easy to do via Amazon.com or Apple.
If he wants to be in a brick and mortar store though, that's a lot harder. He could try some independent bookstores (if they still exist) or otherwise try to get an agent and submit manuscripts to publishers. Obviously they get thousands of those from would-be writer every day. Tough to break into.