This probably isn't much help but I have read that the shifter knob isn't ment to be taken apart, if it is it has to be replaced. I haven't tried it so I don't know if this is true but also someone said that under the chrome plastic piece there is a screw, supposedly the chrome piece will slide down. I have my console apart partially except for the shifter and it looks like on my 06 navigator that they arnt changable, they are little square led units which to m look like they are
Ok so last night I did remove shifter on my 06! Take a small flathead screw driver and carefully pry up from the bottom of the long plastic chrome piece, the bottom will pop out and give you enough room to take out the two Phillip screws in behind and it should pop right off.