Untie any decorative bows that are holding the sofa cover together. These are typically found on the arms of the sofa, but not all sofa covers have ties.
Pull the sofa cover from between the sofa cushions, if it is not held to the sofa by elastic. Continue by lifting the cover from the back of the sofa and then the arms to remove it completely.
Lift the cover from the bottom of the sofa if it is held on by elastic. Follow by lifting the elastic from the back, then the arms and cushions to remove the sofa cover.
Place the new cover onto the bottom of the sofa first, if it is held on by elastic. Pull it onto the cushions and then the arms. Finish by snapping the cover over the back of the sofa, then smoothing it over the cushions with your hand to remove any wrinkles or air pockets.
Lay the entire cover over the sofa, if it is held on by ties. Smooth it over the back of the sofa, push it in between the cushions, and then lay it over the bottom of the sofa. Finish by making secure bows with the cover's ties at the arms of the sofa.