Lift the belt up and over the left sprocket.

Move the belt to the front of the mower, out of the way of the belt tensioner.

During reassembly, ensure all belt teeth are fully seated, otherwise there will not be enough slack for the belt to be installed.

During reassembly, ensure that the blades are oriented perpendicularly to one another so they don't collide.

Spin the left sprocket, with the blade attached underneath, until it is in a safe position, then place the belt on the sprocket.

Spin both blades to ensure they don't touch during a 360˚ rotation.