1999 ford explorer wire molex/box

I've read the post about wiring through a molex from forbidden, and found it wonderfully informative. However, I cannot seem to figure out how to apply the principles to my particular situation. I've got this thing that I cannot seem to disconnect, move, disassemble, or anything. I can't figure out how to even get the thing apart in order to attempt to run wires through it. There's a picture below. Has anyone done one of these before, and can offer some advice on how to run wire through it? Now that I've stepped away from it, and had a chance to think, it appears as though this thing might be some sort of plug that comes apart where it changes from round to sorta squared. Though I still can't figure out how to get them apart.

Hey Mark, Thanks for the info. It's actually right on top. I went back to this in the morning with a fresh mind, and found that pretty quickly. After that the rest was easy. It's a 10 mm bolt on the top. That contoured part on top in the picture is a plug which pops off to reveal it. Yay! Thanks again!