Not real helpful now but I take pictures of each part as I take something apart. Search your machine number and see if there is an on line manual. You can make the page larger and see better details if on line.
This happen to me once with my old machine. Usually the instruction books are very good as they show enlarged diagrams. I have Bernina machines and the instructions are amazing. Hope you manage to fix the problem. Sarah.
The YouTube video should show you what you need to know.
Sorry, I forget that YouTube links do not work here. Got to YouTube and search for: "Heirloom Creations Bernina clean oil bobbin" That should take you there. I can try to add the link with spaces here. Remove the spaces between the www and the . as well as between the . and com. Good luck
http://www .youtube. com/watch?v=hJCRfpO_MVo