I found that this was a really easy project. even easier than replacing my iphone 5 screen. however the replacement screen I purchased from a third party did not have the wires for the webcam connected. they had been severed off. Also the antenna and connectors were not included either so I had to take them from the old broken screen. this was at first frustrating but then I thought about how often I use a webcam and quickly carried on with the project because I really don't need a webcam (and now the NSA can't see me hehe). also the plastic covering for the antenna which is talked about in the retina display teardown as easy to remove was in fact far more difficult for me to remove than anything. I ended up nearly breaking the plastic covering in half trying to remove it.
Overall, this was an easy and painless 2/10 difficulty to perform and had the cords for the webcam been present it would not have made it any more difficult. Piece of cake.