If the temperature inside your freezer seems inconsistent with the temperature that it is set for, you may have a faulty thermostat. You can make sure this is the reason by adjusting the thermostat and checking to make sure the temperature changes in the right direction. If not, you'll need to purchase a new thermostat, which can be installed in a short amount of time.
Unplug the freezer. If the switch to unplug the freezer is in a hard-to-reach location, turn off the breaker switch that controls the power to the room where the freezer is stored.
Locate the thermostat. If the freezer is connected to a refrigerator, the thermostat may be located inside of the refrigerator.
Clear all contents away from around the thermostat. You may need to also remove a shelf or a drawer, depending on how the freezer is constructed.
Use the screwdriver to remove the panel covering the thermostat. Some panels may be connected with clips or in other ways in which a screwdriver is not needed.
Locate the two wires leading out of the thermostat and into the terminal. Use the needle nose pliers to remove the wires from the terminal. Do so gently as to not rip the wires. Remove the thermostat.
Take the replacement thermostat and use the needle nose pliers to connect the two wires to the terminal. Screw the panel back in place and return power to the freezer.
Use the same test to make sure the new thermostat is working that you used to see if the first one was broken.
Check to see if you have the right screwdriver to remove the panel before turning off the power to your freezer.
Electrocution can result if the power is not properly turned off before you begin removing the wires. Don't turn off the power until you are ready to work, especially if there is food in the freezer that can defrost.