How can a residential landlord recover possession of a rental unit?

There are only three ways for a residential landlord to recover possession of the rental unit: (1) the tenant voluntarily returns possession of the rental unit to the landlord (i.e., at the end of tenancy or for any other reason), (2) by court order (i.e., after the landlord has filed and succeeded in an eviction action against the tenant) or (3) after abandonment of the rental unit by the tenant (as "abandonment" is defined under the Act).  At no time may a residential landlord lock the tenant out of the rental unit while the tenant is “still occupying” the rental unit.  Having said that, a landlord can change the locks: (1) after the court has issued a "Writ of Restitution" and the "Writ of Restitution" has been executed/served upon the tenant by the Sheriff or Constable, but that right is conferred upon the landlord by court order and, technically, the locks are being changed by the Sheriff or Constable and (2) after the landlord has followed and completed the abandonment procedure (see ARS Section 33-1370 for that procedure); changing the locks under these circumstances is permissible because the tenant is no longer “occupying” the rental unit.