Tenant moved on 60 day notice date, but didn't confirm.

[Erica Smith]

I gave my tenant 60 day notice to move by December 30th, She was seen on December 29th moving with a u haul truck and her walk through was scheduled for December 30th. She has blocked my number and hasn't returned her keys, I can't get a confirmation from her stating that she moved. She left a few things behind(ac unit in window, food in fridge, 2 dressers, stroller for dog) How do i gain possession of the property(change locks) without having to go through the eviction process. (I'm in NJ, I can't find any laws on changing locks on abandoned apts, only laws on abandoned property)