While instructions can vary slightly depending on the brand of SSD you have, generally you should unplug all cables from your PC and turn off the power supply. Then open the computer's case, fit the SSD into the proper slot, and screw it in. Attach the cables. Once installation is done, check your PC's BIOS to make sure it recognizes the new SSD. Check out Lifewire's guide to installing an SSD for more detailed information.