First time kicking someone out. Sample letter?

[Ashly B.]

Hi there. Posed a bit before about our tenants with cockroaches. We closed on the property yesterday. I misspoke in my initial post - the tenants are actually NOT under lease. It expired in September '14. I read the How to evict a tenant post but it really addresses non-payment/eviction. Since we are just ending a month to month, I'm wondering what, if any formal steps we are required to take or if its as simple as just putting a letter in the mailbox that gives them 30 days to find a new place. Anyone have a sample letter? 

Thinking we will wait til July 1, give them 30 days and also offer their deposit back to hopefully avoid any headaches with it. 

Fingers crossed it doesn't get ugly. Thanks for any advice!