Former Employee Liable for Payments?

My hubby is co-founder & shareholder in a corporation. He was employed as CTO for about a year and was recently forced to resign due to majority changes on the BoD.

The office lease and a company car lease are both in the companies name, but he also had to sign with his personal name and SSN, as the Corporation didn't have a credit history.

Two questions:

How do we get the Corporation to immediately take my hubbys name off those leases and replace it with the name of a current employee/decision maker?

Can my husband be held personally liable for any debt if the corporation doesn't make payments? I thought he was personally protected by corporate law?

Thanks for your advice!!!