To replace the Brush Belt:
You will need a Phillips head screwdriver.
1. Turn the machine OFF and unplug from the wall outlet.
2. Step on the release pedal to lay the handle down on the floor.
3. Remove the Tank-in-Tank and SmartMix Bottle and set them aside.
4. Turn the machine over to expose the brush.
5. Look for the red retainers, which hold the black brush arms and gear-type brush belt in place. Unscrew the two Phillips head screws. Set these parts aside.
6. Loop the replacement brush roll belt around the brush end and the red pulley with the ridges.
7. Alternate holding each brush arm in place while replacing the red retainers.
8. Replace the Phillips head screws and turn until snug.
9. Turn the machine right side up to replace the Tank-in-Tank and SmartMix Bottle.
If you require additional assistance, please call BISSELL Customer Service Toll free at 0870 2250109 Monday through Friday from 9 a.m. to 4 p.m.
This is from the Bissell Site hope it helps
see http://uk.bissell.com/Search/FAQ.asp?FAQCategory_id=1&FAQCriteria=&FAQSubCategory_id=14&SearchMode=&SortMode=&btnSubmit.x=34&btnSubmit.y=11&Page=1&FAQ_id=68
David Tucker
November 2008