Dirt Devil DD9001 Manuel D'instructions page 8

4. Clean The Filter System
1. As shown in figure 1, pull the dust cup switch to the "unlock"
position, rotate the dust cup in turn and take it out as shown in figure
2, 3 and 4.
2. Rotate the filter cover in the direction shown in one, two, three, four,
five and take out the filter cotton upward.