If it's just the lens itself and not the glass surround the camera bump, then it's not hard to do. Get a decent hair dryer or heat gun and a pick of some sort. I use tweezers. Remove the glass pieces, replace the adhesive, then the lens. Normally this process takes about 10 minutes and it's not very expensive. I dont see the parts here on iFixit but, make sure you buy the sapphire glass replacement lens with adhesive.