The internal maintenance of the rented premises is the responsibility of the tenant.
The tenant cannot alter the structure of the building including replacing the tiles inside the house nor the door of the bathroom can be replaced as per his whims.
This can be a sufficient reason and ground to instruct the tenant to vacate the rented premises.
Moreover the tenant cannot demand for the expenses he incurred to which he neither sought permission nor had an authority to do it.
You can refuse his demands and instruct him to vacate or issue a legal notice to vacate the premises due to his illegal activities like changing or altering the structure without the permission of the landlord.
After that you can file an eviction suit in the court of law on the same grounds.