an aux input mod for my wife's 2007 ford sport trac

[driverofchuckles]

I've gone to a few forums for her truck only to find that the members do not actually "mod" anything. So since everyone here is amazing at nodding the greatest little car ever made and helping others to do the same I thought id ask here.

My wife's truck has the factory stereo but was made just before or after Ford started including the input as a standard. I'm wondering if anyone has the knowledge and/or the experience to help me figure out how to splice in a jack. The stereo has an aux button but it seems to be dedicated to the satellite radio, we don't use it. My thought is that I could go through that but I'm not sure just how. Help? Please?