Hey there! I had the same issue last month when my trash can got a nasty dent from a fallen branch. Don't worry – stainless steel is surprisingly forgiving. Here's what worked for me and what other homeowners recommend.
First, assess the dent. If it's a shallow crease without sharp edges, you can probably fix it yourself. For deep punctures or ripped metal, you might need professional help.
The hot water method is simplest for plastic-lined cans. Boil water, pour it slowly over the dent (wear gloves!), then immediately push the dent out from inside with a wooden spoon handle. The metal expands with heat and often pops back.
For larger dents, try the plunger trick. Wet the plunger's rim and the dented area. Create a tight seal and pull firmly. It might take several attempts, but I've seen this work on car dents too!
Some people swear by the hairdryer-and-compressed-air method. Heat the dent with a hairdryer for 2-3 minutes, then quickly spray compressed air (held upside down) on the spot. The rapid cooling can contract the metal and pop the dent out.
After repairing, clean the area with stainless steel cleaner to restore the finish. A little baking soda paste can buff out minor scratches.
Remember: Never use hammers or excessive force, as stainless steel can work-harden and become brittle. Patience is key! Most minor dents come out with these gentle methods.