How To Upgrade/Replace Hard Drive in iMac 27" 2012-2015 to an SSD - YouTube
Amazon.com: PCIe NVMe Gen3x4 SSD 1TB 512GB 256GB 128GB 3D TLC NAND Flash Hard Drive SSD Replacement for Macbook Air 2013-2017, Macbook Pro Retina 2013-2015, iMac 2013-2017, Mac Pro 2013, Mac Mini 2014 (1TB) : Electronics