I need a letter!

I'm having a hard time wording a cover letter to accompany a vacate notice to a resident here. A background: she used to be the manager here. Over the past year she has a tendency to stir the pot, and constantly complain to management about how to do things differently. Encourages residents to goto owners, the health department, certain websites, in order for residents to get what they want. She is breaking the "interfering with management" part of the lease. We have met with her in person, gave her a chance, and it continued. Therefore we are non-renewing. I'm having a hard time wording this perfectly! Here is what I got thus far: Please help!

This letter serves as a follow-up notice regarding the conversation *(&*(&( and I had with you last October. During the meeting, we spoke with you about resident complaints we had been receiving regarding your complaints about the management of Hampton Court Apartment and encouraging them to take extra steps in _____. Since that time, we have continued to receive both verbal and written complaints from residents regarding the above issues.
Therefore we feel with your previous employment that your residency here serves as a conflict of interest and we will be non-renewing your lease.......

Wow, what a mess. I would also cite the part in the lease that mentions not interfering with management.

I have been writing a lot of letters lately and after reading what I write, I find it best to minimize the content to as few words as possible.

So, I write what I would REALLY like to say to make me feel better.

Then I just write:

Your lease expires____ and we are exercising our option not to renew your lease. You may leave anytime between now and this date without the penalty of an early termination fee (I have found that long-term residents usually are paying a lot less than what we are leasing them for so starting a new tenant at the higher rate is very suitable for me.)

If we can help expedite your move, please give us a call. We'll be more than happy to assist you.

Just sent one yesterday.