Eureka is a company that has made top-of-the-line vacuums for years, the Eureka "Boss" model being one of their most popular. The vacuum belt is the heart of the vacuum. Without it, the brush roll will not turn and you will not be able to effectively brush and clean your floors. If the vacuum belt cracks, wears down or smells as if it is burning, it is time for a new one. While there are several different models of the "Boss" vacuum, the procedure for changing the belt is the same for each of them.
Unplug the vacuum while you are changing the belt. Find the control lever that adjusts the height of the brush roll and put it in the "Hard Floor" position.
Check the underside of the vacuum, and notice that there are three screws that hold the base plate on. Use a Phillips head screwdriver to remove these screws.
Gently lift up the base plate and remove it. Lift up the brush roll until it slides out, and remove the old belt.
Slide the new belt around the motor shaft and then around the brush roll.
Replace the brush roll by putting the belt side in first. Gently roll the belt with your hand to make sure it turns correctly before replacing the base plate.
Put the base plate back on by first inserting the four front tabs into the front base slots and then close the rear of the base plate down. Secure the base plate by replacing the screws that you removed in Step 2.