It isn't very hard. You can buy lens replacement on aliexpress or another Chinese site. To replace lens you have to follow these steps: 1. Take out back cover 2. Remove battery 3. Remove SD card 4. Remove all Phillips screws from back of the phone (some might be hidden under rubber caps - see other guides with photos . 5. Pry open the internal back chassis starting from a place near power button (credit card is a great tool for it. Don't use anything metal) 6. The lens is glued to the part you just pried open. 9. Detach the lens (well in fact it is a glass cover with UV filter) by applying some force from internal side of the back chassis to the glass - it should be quite easily pushed outside of the back chassis 10. The replacement lens should come with a glue ring. 11. Apply the glue ring to the side of the lens marked by white dot. Be careful to align it properly before applying. You don't want to make lens dirty, especially from the side facing internals of the phone. 12. Put the lens in the hole, glue...