One of the few interior goodies I wanted to get for my TS was the STi shifter trim. I found a good deal on a complete trim sans boot on eBay, and went about adding it to my TS. It is not a difficult process, and the finished result is nice. If you should have any questions or comments, feel free to email me.
First, start by opening your center console or raising the armrest extension if you have one. You need to remove the trim piece around your ebrake, which will come off with a strong tug. All that is holding it in is some clips- some strong clips. I usually put my fingers in the ebrake area and tug straight up. Pull the trim around the ebrake and push it back a bit. There is no need to unclip the mirror controls.
Next, remove your shift knob- for most folks, it will just unscrew counterclockwise. For everyone else, you probably put the knob on and know how to remove it.
With the knob removed, you simply need pull up and back on the shifter surround to free it.
The naked shifter with all the trim removed. Incidentally, you have about 1/2 of a short shifter install done at this point- all you'd need do is undo that bolt, pop out the old shifter, and whack in the new one with a large rubber mallet. But I digress.
This picture is in here as more digression. This is the rubber ring underneath the shift boot that holds it tight against the shift knob. For most folks, I imagine you will be reusing your stock shift boot, and this bit will not be of interest to you. Go on to the next step. My boot was rather beat up, and I got a stock STi boot, which does not have one of these. If you unroll your stock boot, you will find this rubber piece lightly glued to the leather. I had to pull this off and use it for my install, as I did use an STi boot and not the stock one.
No good photos of the next step, as the trim is black, the boot ring is black, and the damn little clips are black. In any event, if you flip the shifter surround over, you will see the shift boot is held on with very small metal clips on plastic posts. You need to carefully wiggle these off the posts, as you may want to reuse them to reattach the boot (added security, but I did not reuse them). If/when you get frustrated with them and cut them off with nippers, the part number is 92094AC010 and are really cheap. With the clips off, remove the boot and put it aside.
I lost the photo of me working on trimming the shifter surround, but it's very basic- you need to trim out 6 roundish holes to fit the STi trim in place. It's a bit of trim and test fit, trim and test fit to get a nice fit, but it is not hard. You will end up with what you see above.
Next, put your boot back in place on the little plastic pegs, and put your STi trim in place. Using a small punch or awl, you will need to mark the shifter boot attachment ring to show you where to drill small holes for the attachment hardware. If you have an STi boot, these holes already exist.
With your holes drilled, insert the 6 hex cap screws into the holes, and spin on the nuts on the backside.
If you chose to reuse the little clips, you can put them back on now. Using an allen wrench and small pliers or a socket (8mm IIRC), tighten the bolts down snugly. The ridges on the nuts will bite into the plastic, holding them firm, so no need to go overboard.
The completed shifter surround with trim and boot. I added the 5MT shift pattern for a nice touch. You can clearly see the rubber ring I reused with the STi boot- a bit of hot glue helps keep it in place, but the taper of the boot does most of the work.
And the piece installed- you just reverse the first few steps to get it back in place again. Some folks have commented on the color of my STi shifter trim being lighter than normal. The STi trim is usually a little darker than shown here- I have painted it to match the silver trim in the car, as someone used something like Armor All to clean the trim and ruined the finish, requiring a sand and refinish.