There are many reasons why a client decides that one attorney is out and another is in. It can be personal, professional, or even irrational. Whatever the reason, if your client wants to make a swap, make sure you meet all of the requirements for an effective substitution of counsel in California.
Law firms are getting more aggressive about suing clients for unpaid legal bills. As the New York Law Journal says, what used to be “unseemly” may become routine. But bringing a breach of contract action against a client for unpaid fees is a very tricky business: first, you have to get out of the attorney-client relationship, and then you have to invoke your (hopefully) enforceable fee agreement.