We have a YS pedestal as well
but our wheel slides off easily as the rear (or forward facing) face of the wheel hub has the keyway cut in it. I hate to ask the question but are you sure that your wheel hub does not have the keyway cut all the way through so that you can pull the wheel off leaving the keyway in the shaft?
Ours was hard to remove the first time and I thought we had the same problem. A little WD40 and elbow grease got it off for us. If your set up is different then maybe a very small drill bit and screw extractor might get the key out?