Contracting Work on H4

[immihelp]

I am with a Canadian company looking to offer contracting IT work to a Canadian citizen, who is living with his wife in the US. She is working in the US with an H1-B visa.
He apparently can apply to be with her as the spouse.

What would be the process for him to be able to do remote IT work from his home in the US?

Thank you

[immihelp]

If primary worker is on H1, spouse is on H4. Spouse on H4 are not allowed to work.