In the disengagement letter, the lawyer should warn the client of applicable time limitations, deadlines, and uncompleted investigation or casework. An end of representation letter serves as a professional and ethical marker to indicate the end of a specific attorney-client relationship.In this article, we'll explain when and how you should terminate your lawyer-client relationship. We'll even provide a sample termination letter. The case is now concluded. Need to write an attorney closing letter to clients? If you choose the first or second option, a consent to change attorney, or an order of the court removing the attorney must already be e-filed in the case. ❏ Write the client a disengagement letter, signifying that the representation has ended. See sample Disengagement Letters on pages 78-79. Sample Disengagement Letter.