Here's another option before you cut the cowl panel open.
Maybe you can access the hinge pocket from under the dash. The dash support lines up with the hinge pocket and you might be able to get a prybar in there and push the pin down enough to get the hinge out. If the hinge pin is loose enough that it rotates when you try to saw it, it may push back down. You might have to soak it with penetrating oil. Here's a couple of photos. If they look weird, I took them of my cab upside down on the rotisserie and rotated them back right side up (in relation to the cab) That's not a toolbox on the ceiling in the background.
