Take an allen key (the l-shaped type that you'd get with furnture you buy from Ikea, for example). Stick the short end under the bottom edge of the button on the shifter you use to shift from P-R-N-D and tilt it so the button cover pops off. Once this is done, you'll see an upside down "u" shaped metal pin that you have to either press in or pull out toward you (I can't remember). While doing so, you pull up on the entire shifter, and it pops right off.
Took me forever to figure this out as there is little to no info for tip users. I will also see if I can find a link to another forum that had some helpful images.