Anyone know how easy it is to install a stock bmw M series 6speed shift knob? I kind of like the lighted shift pattern one.

 

Can't speak to the E46 M's, but if it's anything like the 5speed, you have an incompatability issue due to the threaded nature of our knobs vice the 'snap' design of the E36 knobs. Also, the original design of the E36 M knobs were two piece (knob and boot two seperate units), but they have since been redesigned so that the knob and the boot are now one complete unit - both consist of the wiring for the lighted shift pattern running along the side into a connector which is located near the transmission tunnel.