My Mother Inlaw ownes a condo that my sister inlaw is currently living in, my mother inlaw wants her to move out but she refuses to do so. What can my Mother Inlaw do to evict her.

The same thing any landlord would do to any tenant. She needs to give her proper notice to vacate. If she doesn't vacate then the landlord files for an eviction order.

The exact process varies by location. So she needs to get the particulars from the local housing court.