New ownership and rental increase

[Genainna Pereira]

Hello Everyone, I just bought my first home and it comes with a rented guest house. The renters is under a month to month rental basis with no contract. His rental is not on market value at all, he pays $1,000.00 monthly, I can rent it for $2,000.00 this afternoon if I wanted to. Yesterday when I came to talk to him about raising his rent to market value $1,800 mostly he went crazy, he was offensive and very pushy, now I don't want him there not even if he paid $5,000 a month. He also said that he'll look into his rights that I couldn't raise the rent that much and he'll seek an attorney. . What do I do? send him a quit notice? under what reason? I just bought the property a week ago. TIA