My Solution
My situation:
Jack was broken off halfway through, in my 2-year-old MacBook. It broke off at the end of the second metal section of the jack (starting from the tip). The metal sleeve of the second actually separated and came off, when trying to remove the broken jack (see pics).
Solutions attempted (In order tried, all FAILS):
1) Fishing it out with a pin or toothpic (the metal sleeve came off at some point here)
2) Crazy gluing the other half of the jack that broke off and tying to pull it out.
3) Crazy gluing a toothpick to the lodged in piece and trying to pull it out.
4) Taking it the MAC store and having them try to remove it with some sort of pliers or tweezers for about 25 min. The 'genius' even got his manager to try.
5) Trying to remove it myself with small pointy tweezers
Solution that WORKED:
Took a small safety pin and fashioned it ever so slightly at the very tip, such the very tip was sticking out roughly 90 degrees from the shaft of the safety pin (see pic). Slid the tip down the side until the shaft of the safety pin is parallel to the wall and the tip is sticking in side of the broken jack. I then pulled it out. It took 2-3 pulls, but it was out in 2 mins, first try with the modified safety pin.
Keep in mind that the pin was pushing into plastic b/c the metal sleeve have come off in my case.
The MAC store recommended I try a hobby shop or maybe a different computer shop. They said that taking it apart is of no use b/c it's not accessible that way. If it can't be somehow pulled out they would have to replace the logic board which would cost $600CAD, plus labour.
This is an extremely frustrating problem. Best of luck.