You could try loosening up everything... yoke, triple tree, front fender. Wiggle everything around and see if it's out of alignment. If it's still stuck you'll prolly have to take the forks apart.
One other thing I just thought of..... could be the PO overfilled the fork oil. You could try draining it and putting the correct amount back in.
Also, while you're working on the front end, make sure the rear is held somehow... tied or weighted down so the bike doesn't fall forward when the forks collapse.
Even a floor jack and piece of wood under the engine.... something to hold the front end up.