Last Christmas, my sister received a set of Samsung Level U wireless headphones.
She didn't like them, and so she gave them to me. I liked the convenience of the wireless headphones, but didn't like the earbuds that came with them. Just swapping out the earbuds would have been to easy, so I decided to replace them with a headphone jack.
My first problem was trying to get the set apart. (If any Samsung engineers are reading this, next time please use more screws and less glue.) I was able to remove one of the side stems by sliding a razor blade under the rubber and carefully prying the rubber off the mount. With the side stem removed, I was able to pry the rest of the set apart.
Here is what I found inside.
For the sharp of eye, yes I did accidentally disconnect the right headphone wire when I was prying open the case.
I think that this strip of wire is the antenna for the Bluetooth module. it contacts the spring on the left hand board.
With the set disemboweled, it was a simple matter to disconnect the earbuds, and replace them with a spare headphone jack from my parts bin.
I later moved the red wire to the upper solder pad, because It provided better sound.
Both the jack and the case required extensive modification to make everything fit. (Another tip for Samsung engineers; leave enough room in your devices to allow for unauthorized modifications.)
There was barely enough room to run a wire across the set to reach the jack.
After I got everything wired up, and modified the case to fit, I glued everything back together, and used shrink tube to hide the holes from the original earbuds.