Put on rubber gloves and place the dry ice into the bucket next to the refrigerator.
Turn on the heat gun and aim it at the dent, a few inches away from the surface, for about 45 seconds.
Set the heat gun down safely and quickly grab the dry ice with your gloved hands. Hold the dry ice directly against the dent for about 15 seconds.
Remove the dry ice and watch to see if the hot and cold help remove the dent. Leave it alone for a minute. If the dent remains, repeat the hot/cold application process.
Use a toilet plunger on the dent if the hot/cold method does not work. Center the plunger around the dent, push it in against the refrigerator, then remove the plunger quickly. The suction created by the plunger may remove the dent.
Call a professional if the dent remains.