How to Safely Remove a Chain from Your Mountain Bike
To take a chain off a mountain bike, first shift the gears so that the chain is on the largest front and rear sprockets. Then locate the chain tool and insert it into the chain with the pins lined up with the chain links you want to remove. Turn the tool until the pin pushes out the link. Repeat this process until the desired length of chain is removed. The chain can then be easily slid off the bike’s gears and derailleur.