I did a cover off on my Euro 500SE ,and it was a good thing I did as one bottom rail was paper thin.I also replace the oil pump chain and it's rail while I had it open.I would try bp blaster and a little heat around the tube then try twisting it back and forth I think if you hit it from the bottom even with a tight fitting socket you might mushroom it, even a tiny bit would make it nearly impossible to take out...........

William Rogers.........