Try to find peoplewriting in your apartment. Maybe they agree to leave voluntarily. If you wish, offer them compensation (compensation). Unilaterally, you can't write.
If you haven't found or written refuse to leave – sue in court. In accordance with the Housing code of the Russian Federation the court will consider the right of use of premises does not reside in it.
Collect evidence that citizens do not exist not for a good reason (business trip etc). Confirm the documented evasion non-resident from obligations for payment of utility bills and maintenance of the housing Fund. Gather other evidence that prescribed do not actually live in the apartment and do not have the burden of responsibility for it.
The claim requires sufficient grounds and evidence. Refer to the help of specialists.