Check out this video:
http://www.youtube.com/watch?v=zjYlr...embedded#at=25
About half way through the video, at about 4:21, he begins explaining how to change the light bulb on a FW. I highly recommend his book and/or DVD set. I have both and use them all the time.
I've bought machines on eBay that were smashed to smithereens and others that came in perfect condition. You just need to check out whether the seller has mailed a sewing machine before, or not. Also, ask them ahead of time how they plan on packing it for shipment.