Okay, let's start with the basics:
Does the shift light have 3 or four wires.
Three wires, should be Red, Black and the third we will call X.
Red to a positive feed that is controlled by ign on or off. use a meter in your fuse box to locate.
Black, this goes to ground. While many people like to daisy chain off of the ground wire behind the stereo, do not do so, just run the wire to your firewall and attach.
X goes to the #8 green wire that is Already in your car. This is the 2001 tach feed wire, even if your car has no tach, the wire is there, this is what let's the car know how fast the engine is running. This is located under your left foot when you drive, you cannot miss it.
Four wires, see above, but the difference would be red same, blue to the battery, black to ground and the color X to the tach wire.
If you did not understand the above, or are unsure then have someone else install it at a shop and look and see what they did to learn.