Advice for firing my PM to go Owner Managed

[Liz Norman]

How do I go about firing my PM? Long story short I'm the owner of a property managed by a PM co. We've had the same tenants for the entire time, roughly 4 years. For the last year or so we've had issues with our PM and they're essentially no longer responding to my inquiries and owe us money for "accounting errors" and late fees not collected, which they have been notified of multiple times to no resolution and minimal response. Should I notify my tentants first (my only contact info is mailing address) before I send my PM certified mail notification that I'm terminating our contract? Do I send PM notification of termination first? I'd like to retain the tenants and will likely keep their lease terms as consistent as possible beside who they're remitting payment to. What is the process here?