I don't quite understan your question.  Why change shifter bushings?  To
remove the slack in the shifter of course!  The Nylon bushings right
underneath your shifter are probably worn right out.  Get some new ones from
honda for $10, put them in, and its like you are driving a totally different
car.

t

You would replace the shifter bushings if your shift lever buzzes, or feels
unusually sloppy.

See this sketch:
http://www.tegger.com/hondafaq/misc/shifter_sketch.jpg

and:
http://www.tegger.com/hondafaq/misc/shifter.jpg

I haven't got around to making a Web page for the bushing replacement I did
last month, but you can look at each individual image here:
http://www.tegger.com/hondafaq/misc/bushing_kit/
Once I've got them edited and Photoshopped, they'll make more sense.  

From the above, it should be apparent that the shifter assembly is secured
left-to-right by the rubber donuts that I've drawn in black in my sketch.
They are the things that keep the two clevises from rattling against each
other. If they perish, the lever portion will not be firmly against the
tranny portion, and there will be about 1/8" of play at the join between
the two. For a while, the four O-rings on the yellow sleeve will keep
things quiet, but eventually they will wear as well.