I'm a little confused what you're having an issue with. The jack that comes stock in the glovebox has two ends: one on the stereo side and one on the glovebox side.
If the issue is that you can't get to the glovebox connector to remove it, you're working from the wrong end. The glovebox connector has an unusual washer arrangement around it from the glovebox side (right there visible from the passenger seat) where the the center/top piece pops up to allow the surrounding/bottom fingers to decompress so they can release from inside the ledge of the mounting hole. The connector will drop out the back of the hole if it's quick about things.
The standard connector size in the glovebox is 3.5mm (reference: smart Operator's Manual).

First image is the grommet apart, second image is back together.
Click for higher resolution image.