Turn off the vacuum and unplug it from the electrical outlet. Lay the vacuum on the floor facing down with the brush roll and base exposed. The wheels and their assembly are visible.
Pull the wheels and shafts off of the vacuum.
Attach the new wheel to the vacuum, and push the shaft through the hole on the wheel. Attach the clip with your hand on the inside of the wheel to hold the wheel in place. Repeat the process to attach the other wheel.