Ditto. The sleeve they must mean is the outer sleeve. It is actually welded into the control arm. If you look at the control arm from the top or bottom (one or the other) you will see the outer sleeve the manufacturer is talking about leaving in.The (inner) sleeve is what I call the metal sleeve that encases the rubber bushing. There is a third bushing inside the rubber bushing. In other words, the rubber bushing is sandwiched between it's own sleeves. Have them pressed out as this will cause less stress on the arm. I just did this to my car.