Can't say that I have ever removed a stock shifter for that reason before....it's usually only been when removing the trans. I would think that you could remove the shifter cover in the console, and prolly part of the console, and get to the 4 bolts that hold the shifter to the trans. If not, you can get to the bolts from underneath, tho it is a tight fit unless you remove the "C" shaped torque bar from the trans to the diff. If you do that, you'll need a jack under the trans to keep the engine/trans from tilting back far enough to damage the firewall.
Maybe someone else here can chime in on changing shifters on the late C4s....
______________
Joel Adams
My Link

(click for Texas-sized view!) NCRS
"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"