Ok - first - to get the cams out - these are the "top hat" type of cams. They just snap in & snap out. So just firmly grip the "top hat" part & firmly pull it out.
For a manual - try searching E-bay. Here's what came up for me:
http://shop.ebay.com/i.html?_from=R4...All-Categories
or - you can order a replacement manual direct from Singer:
http://www.singerco.com/accessories/instruction-manuals
Hope this helps. :)
ETA: jljack's link is even better! A free manual always beats having to buy one.