I don't know what the replacement is, nor where to get them fixed (might get an address and at least send them to Nikon service, as they may replace of repair with a cost estimate).
I do wish I had purchased the Bushnell binoculars with the built-in digital camera that I saw at Sam's last December for around $150. May have not been the best optics, but have thought of several times where a close-up photo of what I was viewing in the binocs would have been great to have digitized. I don't remember much of the details, but 8X rings a bell.