You can't, because they can't legally operate like that in the US.
Deloitte: https://www2.deloitte.com/us/en/pages/tax/solutions/legal-bu...
> The Deloitte US firms do not practice law or provide legal advice. Deloitte Legal refers to the legal practices of Deloitte Touche Tohmatsu Limited member firms (or their respective affiliates) that provide legal services outside of the United States.
PWC: https://www.pwc.com/us/en/services/tax/legal-business-soluti...
> PwC US does not provide legal advice or opinion in the United States
Lawyers in the US, through the state Bar Associations, have done a damn fine job of protecting their industry against capital. Doctors in the US now answer to MBAs, Lawyers only answer to other Lawyers.