Using the Shotgun Dirt Hero balance bike is easy. First, make sure your child is wearing proper safety gear like a helmet. Then, help your child sit on the bike and hold the handlebars. They can start by pushing off with their feet to get moving. When they want to stop, teach them to use the hand - operated hydraulic disc brake. As for convertibility, if you want to switch from 12 - inch to 14 - inch wheels, follow the included instructions carefully. When it comes to maintenance, regularly check the tyres for proper inflation and any signs of wear. Wipe down the bike after each ride to keep it clean. Also, make sure the brakes are working well. If you notice any issues, don't hesitate to contact a professional bike mechanic.