Eviction of tenant and action regarding threat

We want to evict our tenant as he is causing a lot of personal problems like entering our premise without our permission especially when we take our baths and the women are not clothed (not just a coincidence. Has happened more than 10 times) and he also is a sly person. We also want to pursue with some renovation work in the flat. He is an old man and has been staying there since 2010. His agreement was renewed in May, 2015. It will expire in 3 yrs from the date of renewal. On what grounds can the eviction be made? And how many days notice period should we hand him?The lease has many loopholes and does not state any eviction clauses. Also, his late wife's relative is a member of a political party and has decided on interfering in this matter on the grounds of him making a "promise" to his late wife that he will take care of this old man. He hasn't directly threatened us but has said "in case of you not letting him stay there we definitely will have to make some arrangements and we will definitely make arrangements in keeping him there itself" We do not want to rent this old man the flat anymore. Please tell us how can we safeguard ourselves and proceed with evicting him.