Legal Confirmation Regarding Business Partner's Exit

I am in need of assistance to obtain two confirmations - one from the IRS and the other to verify the exit of a business partner. While I am not currently certain if I require official copies, I am open to recommendations. I also require partial guidance for understanding the legal process revolving around these confirmations. Ideal candidates for this project would have a strong background in corporate law, particularly with IRS matters and partnership agreements. Understanding of complex legal processes and ability to simplify and communicate these effectively is also desirable.