How to evict tenants not paying rent in central NY state (cortland)?

Before I buy this small motel property in central NY state i would appreciate someone's help .I want to know this motel has some Monthly tenants and some do not pay any rent from long time and they create disturbance to good tenants how can i evict them from this property if i decide to buy it, the current owner said there is no lease document or no security deposit taken from them, please advise.