iPhone 6s Plus camera broken—fixed it and replaced the battery as well!
My wife's iPhone 6s Plus had a broken camera for about 6 months... AND the battery wasn't keeping a charge.
Repair went great. I bought the replacement camera from iFixit.com, and followed the guide with no issues. I also replaced the battery using the battery replacement guide, and had a bit of trouble removing the adhesive strips that between the battery and the back plate. Actually, that was what took me the most time out of the entire procedure.
Once that was done, everything else was fairly easy.
Be patient with the battery removal process, and do your best not to bend it, or it may puncture and catch fire. I had that happen to me with an iPhone 6 battery I changed the same day I did this procedure.
So far, the camera is working perfectly, and the battery keeps a good charge.