Notice to Quit needed, or just Letter?

[Christopher Reynolds]

Hello everyone. We are buying our second property today! We received the rent roll of the property, and one of the tenants is behind on the rent. We also noticed that every time we visited the unit, we found that several people seemed to be living there, though there was only one person on the lease. Also, the place reeked like Cheech & Chong's apartment. We'd like them gone for several reasons.

We buy the house today, 5/29 at noon. His lease automatically renews July 1. Massachusetts requires a 30 day notice, which would be June 1.

My question is: what kind of notice do I give? Do I actually serve him with a proper 30 day Notice to Quit? Do I inform them with a letter that states his lease will not be renewed? I plan to have a constable serve him the notice, whatever it needs to be.

I'm asking this question because I understand the reasons for the 14 day (non payment) and 30 day notices to quit, but given that we're declining to renew instead of asking them to leave for another reason, I wasn't sure what the proper method was.

None of the replies will be considered legal advice. Thanks!