My tenant won't leave after the contract ended - how do I get my property back?

A contract expiring doesn't auto-evict. You need a valid legal ground plus a proper 12-month notice, or an unpaid-rent judgment. If the tenant still refuses, file at the Rental Dispute Centre for an eviction order; the Execution Department then enforces the handover. You cannot remove them yourself, and a registered Ejari is required to file.