Unplug the vacuum cleaner.
Flip the Hoover vacuum cleaner over and remove the bottom access plate by inserting a screwdriver into the attachment slots, one on the left side and two on the right side, and pushing the screwdriver to the rear once inserted. This will release the tabs and allow you to pull off the bottom plate.
Flip the vacuum cleaner over and pull off the nozzle control knob. Firmly grasp the knob and pull it straight up until it releases and comes off.
Turn the vacuum back over and release the four tabs that hold the top cover on. There will be two slots near the wheels and two slots near the agitator ends. As before, insert a screwdriver into the slots and push the tabs backward. You will be able to remove the top cover afterward.
Pull the agitator out on the side that the belt was attached to. When looking at it from the bottom, this will be the left side of the agitator. Slide the belt over the agitator and position it into the belt guide, lettering side out. Push the agitator back into place.
Loop the belt around the motor driveshaft pulley. You may need to stretch it to fit, but this is a normal procedure. Once seated on the pulley, rotate the agitator to make sure it spins freely.
Snap the top cover back into place, then snap the bottom plate back into place.