[landlord - Us -nj] Tenant Is Required To Vacate By Tomorrow But Has Disappeared. Am I Allowed To Enter?

I’m a landlord in Jersey City, NJ, dealing with a tricky situation. My lease was with a tenant who stopped paying rent in August 2024. I took them to court, and through a Superior Court judgment, they agreed to vacate by January 31, 2025.

However, I am now suspicious that the tenant may have been subletting the unit without my consent. I don’t even know who is staying there now (if anyone).

My questions:

1. If no one answers when I go to check the unit tomorrow, am I legally allowed to enter? The court order requires them to vacate by Jan 31, so does that mean I can assume possession on Feb 1?
2. If there’s stuff left inside but no one is there, can I legally change the locks?
3. If the subtenant(s) are still there, what’s my next step? Do I need to serve them a separate eviction notice, even though my original tenant had no right to sublet?

I want to handle this legally and avoid unnecessary issues. Would love to hear from other NJ landlords who have dealt with something similar. Thanks in advance!