Janie,
Skip the WD-40 it doesn't really do that much good for rusted up parts. That's why I suggested the penetrating oil. I had a 99 that was rusted up very badly and it took me almost a month of soaking and coaxing to get it freed up. It's sewing now. You can do it, just have patience. Sometimes it takes time for the oils to soak into the cracks and crevices. You might also try heat from a hair dryer, sometimes the heat along with the oils helps free up rusted parts.
Joe