Need to change sensor in Liebherr freezer

Hello, I need to replace the sensor in the refrigerator (located in the freezer section), the refrigerator brand is Liebherr HC1050. The sensor is new already, it just needs to be replaced. The problem is with one screw that was damaged when screwed on, so it needs to be unscrewed somehow, the cap is completely twisted. If you can do this, then write when and how much it will cost. I am in Manhattan, financial district, near the Fulton Center.