It is a bit of a weird jack. From the way it looks, your need some sort of socket to remove the nut from the inside to get it loose. Is it easy? That is the one of the few things I haven't messed with on that bass, so I wouldn't know. Pictures probably wouldn't come out good unless you hada good flash, since the back cavity is "shielded" and dark. My fear is the stripping of the outside part of the jack as I would try to grip it with a pair of pliers or something while removing the inner nut.
It's things like this that keep my curiosity in check, and my constant need to take things apart and try to put them back together. I have nice basses, I don't wanna f@#$ them up too bad.
Tricked Out Squier Club #45, M2B2 Club #12, Squier MusicMaster Vista Club Member #5