Disclaimer: The following is provided as a GUIDE ONLY, and neither myself, nor FITFREAK.NET endorse, recommend, encourage nor take any responsibility for the outcome of someone else doing the following. You follow these steps at your own risk!
Tools: 12 mm socket/rachet, needle nose pliers, flat & phillips screwdrivers
Time: an hour or less
Instructions provided are in Japanese with a few pics. I don't read Japanese so I'm winging it here.
Remove the gear shift knob by turning counterclockwise.
Carefully pull out the plastic plug under the e brake handle

.................................................. .................................................. .
There's two plugs in the front of the center console that look like this. Push the center part and it will pop the plug right out.

.................................................. .................................................. .
Remove the two phillips screws that hold the back of the console on.
.................................................. .................................................. .
Now lift up the back of the console and unplug the 12volt outlet wire (yell/blk) and for you sport owners the audio jack wire.
.................................................. .................................................. .
Next pry up the two white plugs that hold the wire loom down on the right side. One at back one on front right.

.................................................. .................................................. .
Here's a pic of one piece of the linkage, a cotter pin has to be unbent and removed. Next take off the black washer and slide the rod end to the left off of the white post. A new cotter pin is included with this kit.
.................................................. .................................................. .
Next remove the black piece shown here. There are two black plugs under the edge of the carpet that can be pryed up to remove this section. Carefully tilt it to remove the front part from the center dash.

.................................................. .................................................. .
Here is what it looks like so far. The linkage on the left (black piece) has to be turned about a quater turn counterclockwise to remove it from the white shift assembly (already turned in this pic, just lift up to remove). The linkage on the right has already had its holder removed (a piece of steel has to be pryed straight up). A new steel piece is included with this kit.
.................................................. .................................................. .
Next take out the four 12mm bolts holding the assembly down. Look underneath and pull apart the black wire that holds the white piece to the shifter shaft. Don't bend it out of shape, you need to reuse it.
.................................................. .................................................. .
Install the new shift assembly in reverse order and don't forget to hook up the 12 volt & audio plugs. Here's the new assembly.

..

..

..
I measured from the dashboard to the center of the shaft without the shift knob for the following:
Stock neutral: 7 1/4 inches
Mugen neutral: 7 3/8 inches
Stock 3rd gear: 5 1/2 inches
Mugen 3rd gear: 5 7/8 inches
Stock 4th gear: 9 1/4 inches
Mugen 4th gear: 8 7/8 inches
Stock shaft height above console: 5 1/4 inches
Mugen shaft height above console: 4 1/2 inches
Approximate throw from 3rd to 4th:
Stock: 3 3/4 inches
Mugen: 3 inches
Sorry no driving impressions yet but it feels nice in the drivway

Hope my instructions help, you can do it!