Shelbie is correct about the wick under the bobbin case. My dealer told me to try one drop and if it absorbs quickly, try a second drop. If it doesn't soak completely in, use a piece of cloth to get the excess out. The other locations that need to be oiled are internal and are taken care of during your yearly maintenance. I have done this myself on the 6500 but don't think it would be a good idea on the 6600 unless you have okayed it with your dealer. (Most dealers won't tell you anything about doing the oiling yourself.)