[7Figures2Commas]

Perhaps what you have is worth fighting for, and you will therefore be willing to incur significant costs (in time, energy, opportunity and likely money) battling your co-founder. But I think you should consider the facts you have presented in your question and responses to other comments:

1. Your co-founder has the same level of ownership as you.

2. He controls the company bank account, passwords, etc.

3. His relationship with the board is stronger than yours.

4. Your employees like him.

5. He is aware of your desires and has made it clear he is willing to fight your efforts, apparently even if it means sabotaging the company.

Given these facts, I think it would be wise for you to consider what you can realistically achieve even if you are successful in removing your co-founder. You may find that the question, "How do I fire my co-founder?" is not the first one you should be asking yourself.