Ditch Witch J20 shaft/pulley removal.

[cholder777]

I have a ditch Witch model j20. I'm trying to remove the shaft extender that leads from the large pulley through the rear firewall into the gearbox that powers the trencher. The bearing went out and I need to replace it. Does anyone have any experience removing this pulley? There's very limited space on the end of the pulley, I doubt I'll even be able to fit in Allen wrench on the face of it.