After cracking my lens cover and finding this thread, I purchased a new one from eBay for about $14 with shipping. I was able to replace the glass by using a small screwdriver to remove the broken glass and scrape the adhesive off the back of the cover. Then I just pressed the new lens cover on and I was done. I took the back off my Nexus while doing this and found that while this wasn't strictly necessary, I would still recommend doing it to avoid accidentally damaging the camera.