small metal blade, as the hole in this is quite deep cut a groove either side (carefully) and get a screw driver in there. Rather crude but it worked for me! Fingers crossed the seatpost comes out. If not turn it upside down, pour some coca cola down the tube and leave to soak. Alloy to alloy corrosion is common with Vitus and Alan.
Does that really work? Can't see how you'd get the leverage on a straight screwdriver/blade once you'd got it into the old Allen key slot!
May have to rely on the tip for coca cola, as the saddle bolt on the seatpin is also corroded, as was the stem/bars!
At least the stem/bars are free and out now, but it wasn't especially easy - clear evidence of corrosion on the stem quill. Just can't get the purchase on the Allen bolt, but picked up a slightly too large 10mm Torx bolt and have hammered it into place - currently soaking the bolt, seatpin and seatpin bolt in "Crack It" (which comes out surprisingly cold actually) at regular intervals to give it a better chance of being loosened with minimal damage...
If this doesn't work - the reverse drill bits will be next!
Rossin Concept MTB 1990 - Full XTR M900
Litespeed Ocoee Titanium MTB 1992 - Grafton / Bullseye / Syncros / XTR
LeMond Z Team Issue SLX 1991 - Full Corsa Record / Sigma
LeMond GAN Team Issue GLX 1993 - Full Dura Ace (7400)