Yes, you have to remove the freezer. There should be a trim ring around it with screws. Once removed you can pull the freezer out. I doubt the problem is dirty coils, but it can't hurt to clean. Before cleaning look carefully at the coils, tubing and compressor for any sign of oil. If so this normally indicates where the leak, if any, is. I would also check to see if the compressor is running when powered by feeling for vibration. Also check to see if the cooling fan is running. These units are normally controlled by a Secop 101N0212 controller, which I have had to replace on many units. There are ways to troubleshoot the Secop controller with a led bulb to flash a trouble code, search the internet for the manual.