I made a short shifter for my automatic transmission a few years ago. It's not very hard. It's what I'd consider a "quickie project", i.e. only an hour or two. Here's the run-down:
1) Remove the shifter assembly from the car.
2) Measure and record the dimensions for the slots in the top of the shifter arm. There is a big vertical slot that the knob slides onto, plus two smaller horizontal ones that the retainer clip for the knob fits into.
3) Remove the plastic plunger from the shifter arm. It resembles a string of beads, and goes down the center of the shifter arm. Now you have two choices: cut the plunger to length (i.e. cut off enough "beads" off the bottom to get the length you want), or make a new plunger cut to your desired length.
4) Cut the shifter arm to match the plunger. So if you cut an inch off the plunger, then you need to cut an inch off the shifter arm. It's important that you reduce the length of both parts by the same amount.
5) Cut the slots in the shifter arm, so you can mount your knob. A Dremel tool or a die grinder with a cutting disc should work well for this (I used my Dremel).
6) Re-install the shifter assembly. You're done!
[This message has been edited by Blacktree (edited 06-14-2010).]
