To fit the belt you must position it around centre of brush. replace brush roller , fit trim and clamp into place.
Twist plastic , which has intructions regarding this operation on it, round so as to align arrows marked `belt off`.
Then, with finger, place belt around Metal hook within.
Then, twist plastic round thus stretching the belt up and over so that when you replace the unit, the drive shaft will be within the belt.
Having now replaced the brush assembly you then twist the plastic back round the other way, thus allowing the belt to settle round the drive shaft.
This is a tricky job but is achievable
Good Luck.
Ray Brooks, April 2006