Okay little buddy, let's think about your favorite toy car. When it needs fresh wheels, a mechanic is like a super helper for real cars. They can change the tires very fast, just like how you can put new stickers on your toys quickly!
First, they take off the old tires, just like taking the caps off markers. Then, they put on new tires, which are like giving your car fancy new shoes!
Filling the gas tank is like giving your car a drink. The mechanic uses a special hose, like a straw, to put gas in the tank so the car can go VROOM! This all happens super quickly, usually in just a few seconds, so people can get back on the road, just like when you hurry to get your toy set up to play with.