Dell Precision M4600 Hard Drive Replacement - iFixit Repair Guide
Dell Precision M4600 SSD Upgrade - YouTube
SSD Upgrade for Dell Precision Mobile M4800 (2 slots) 256GB/512GB/1TB/2TB | eBay
Amazon.com: Laptop 2nd HDD SSD Caddy SATA3 Second Solid State Drive Enclosure for Dell Precision M4800 M6600 M6700 M4600 M6400 M6500 M4700 M4500 M4400 Mobile Workstation, CD DVD BD Optical Bay Replacement :