OK,.. here we go:
You've probably already done a bunch of this, but I thought I'd illustrate the process from the beginning, for posterity.
Step 1: Remove the screw with the arrow pointing to it.
[ATTACH=CONFIG]371132[/ATTACH]
Step 2: It'll look like this when you've removed it. Once it does, flip it over.
[ATTACH=CONFIG]371133[/ATTACH]
Step 3: Flip the latch up and push it out of the bobbin case (Sort of North North West on this pic)
[ATTACH=CONFIG]371134[/ATTACH]
Step 4: Use a screwdriver to hook and push the spring out of the slot. (Towards North North East on this picture)
[ATTACH=CONFIG]371135[/ATTACH]
Step 5: Yay! The spring is out!
[ATTACH=CONFIG]371136[/ATTACH]
Step 6: Installation is the reverse of removal
Slide the Spring into the slot where the top arrow is. Then slide the latch back in making sure that it sits inside the slots
[ATTACH=CONFIG]371137[/ATTACH]
Step 7: Grasp the latch and pull it toward you. Sometimes it also helps to push from where the arrow is. Flip the bobbin case back over and reinstall the screw.
[ATTACH=CONFIG]371138[/ATTACH]
Step 8: Test the latch to see that it moves smoothly and snaps back the way you expect.
[ATTACH=CONFIG]371139[/ATTACH]
See the next post for something that you might as well do while you're in there..