>I have a Nikon D 800E and my Nikon 500 VR f4.0 lens attached. >I have been shooting with this combo for quite a while. Combo >works perfect. Any ideas on how to remove the lens?
It's an unusual problem.
The only time I've ever encountered it was on a D700 - twice. A friend came to me with the camera, apparently unable to dismount the lens. It turned out that he was not depressing the lock button on the front of the camera. Problem solved.
The second time occurred with a stranger who was using a D700 with a 300mm F4 at a conservation hiking trail area near my home. The mount was admittedly tight, but the guy just wasn't using enough torque to rotate the lens on the mount after depressing the lock button. I helped him out, but the amount of torque needed didn't seem excessive at all to me. I think his expectation might have been that the dismount should occur absolutely smoothly and effortlessly, but some lens mounts are slightly tigher or looser on some bodies.
Anyway, in neither case was there an actual problem with the cameras or the lenses involved.
A jammed mount or over-rotated lens is really, really rare.