I assume you are the "tech" for this person. Leaving the partnership and starting his own company will now require:

• New EFIN application, which should have been started last year, so hurry up
• New EIN if he is to have employees, or maybe just so he doesn't have to put his SSN on each return
• New account with ProSeries, including a new Fast Path and confirmation of the new EFIN
• If the old firm gives him files, they should be able to be opened with the new firm information in them.

HE should call sales to  work this out AND get busy with getting his new ducks in a row.