Know-How Exchange : Strategy

I am purchasing a dental practice from a dentist who has only been in this location for 1.5 years. The dentist who he purchased it from was a well-respected clinician and a very successful dentist who simply retired. Unfortunately, the new dentist fired some staff, disrespected the retired dentist, and, in turn, alienated some patients who no longer come to this practice. What would be the best method to go about contacting these patients, apologizing for the exiting dentists actions, and explaining that the new dentist (me) wishes to honor the legacy of the original founder of the practice, uphold his values, and treat them like they were used to being treated? I want to make this practice the success that it was only a few years ago...please help.