Extremely easy and cheap fix. Replacement lens is available on eBay for about $6 shipped.
1. Take the phone cover off.
2. Pry the silver bezel off.
3. Pry or rake off the cracked or broken lens.
4. Scrape off the black adhesive residue.
5. Clean actual camera lens to ensure no dust is on it.
6. Peel backing off new lens and stick it on.
7. Peel backing off new bezel and stick it on.
8. Reinstall phone cover.
9. Enjoy not being out $70 bucks and two weeks with a loaner phone.