Change the brush roll and or drive belt, remove the hood screws, which are situated adjacent to the rear wheels (see fig. 1).
Lift the hood off (fig.2).
Change the drive belt even if it is not broken, because they do stretch with time. Before changing the belt roll the brush to see if it rotates easily. If it is stiff to rotate or the bristles are thinned out or damaged then change the brush roll as well (fig 3).