Dismiss him as, from...?

Hi, I want to use 'dismiss' in the context of 'fire'.

Tom is a general manager, and the board of directors dismiss him, and he lost his position.

In this context, which is correct?

"We dismissed him as a general manager"

"We dismissed him from a general manager"

or.... is 'dismiss' not a proper verb to use in this type of sentence?

Thank you for your help again in advance!!