freezer intermitently warmed to around 31 degrees

Being a jet mechanic I had to familiarize myself with refrigerators, then after 2 or 4 hours of online studying, opened the door pulled the temp knobs of, removed the panel by gently prying the top of the panel out,then up and out with it. I found tapping on the thermostat shaft or wiring connection started the compressor, verifying my belief it was the thermostat. Don't mess with wiring if you don't know exactly what you are doing and unit is plugged in, you will electrocute yourself!!! I received the thermostat, UNPLUGGED THE UNIT from the house wall outlet, took one screw out of the upper inner wall at the very top to remove cover, one screw at the back top to remove the other cover (at the control vent) for access to remove sensor, then removed 4 screws , 2 front, 2 underneath to drop the housing for defrost timer, etc., and then took 2 screws from thermostat, unplugged wiring from thermostat (3 wires, be sure to put them back on the same place in the new thermostat). Remove old thermostat, slide plastic cover off sensor and slide back onto new thermostat sensor. Be careful not to kink the line or bend it to sharp you will damage it, (use gentle curves when bending it,) and re assemble everything in reverse order. This took about me 15 or 20 minutes start to finish. Plug into wall and watch thermometer to verify success.