This guide is missing the most strenuous and difficult part of this procedure. Don’t be mislead, installing a new CPU into the socket in a 27” 5K iMac A1419 & A2115 takes major time and patience, due to the fact that Apple uses a proprietary heat sink that makes it impossible to be certain that your CPU didn’t slip out of place while you are literally flipping the whole unsecured logic board around to access the screws to secure the socket. IFixit makes money through traffic on their website. They obtain this traffic by downplaying the complexity of device repair and they do this with beautiful photos, clean white backgrounds and simple instructions but beware because its all BS to get you to believe you can do it yourself when really, you should be hiring a professional