An attorney can be fired by a client with or without cause.  A substitution of attorney form is filed substituting the client as the new attorney in pro per (in pro per means the client is representing himself).  When the client finds a new attorney, the new attorney signs the substitution of attorney form so that he/she is now the attorney of record.  If you find another attorney for your brother before dismissing the current attorney, your brother would not be substituted in for the former attorney.  Instead the new attorney and the fired attorney would complete the substitution of attorney form and the new attorney would become attorney of record.One problem is that the original attorney will probably assert a lien for time he has spent on the case that has not yet been paid.  So, your brother would end up paying that plus the new attorney.  The first attorney's retainer agreement with your brother may have some language regarding compensation if he is dismissed. If there are fee disputes with the attorney, your State Bar may have fee arbitration.