Unscrew the bellcrank assembly from the axle, and pull out the pushrod you will find inside. Loosen the axle nuts and remove the wheel. Removing The Rear Wheel From A Derailleur-Equipped Bike Shift the rear derailleur into high gear, the smallest sprocket. Let the air out of the tire. Loosen the axle nuts to remove the wheel, being careful not to damage the brake pads.
Many bikes have a way to open the brake wider to make removal of the wheel easier.
Look for a way to unhook the short brake cable from one side of the brake if you have a fat tire bike, or a lever to open the brake wider on a thin tire bike. Take your time to see how the chain comes clear as the wheel slides out of the bike. And, please link your web pages to mine.