Unzip the outer Oreck bag completely.
Grab the cardboard collar at the top of the old bag and pull it away from the bag dock door.
Pull up on the collar to remove the bag from the bag compartment. Dispose of the old bag.
Grab the replacement bag. Pinch the front and rear of the bag and pull the two ends away from one another to give the bag bulk.
Fit the replacement bag into the the Oreck bag compartment, with the cardboard positioned at the top and facing the vacuum.
Slip the cardboard collar onto the sleeve of the bag dock door. Push the bag dock door back against the vacuum until it snaps into place.
Zip the outer bag closed.