List of Steps and Things You’ll Need
Internal Hard Drive (SATA or IDE, though you need to know which type when purchasing your kit)
Hard Drive Enclosure Kit (available from a variety of merchants at a variety of prices--remember to check the type)
Screwdriver (to assist in closing the case around the drive, though some kits may come with one)
Anti-Static Bracelet (optional, used to discharge the static when handling an exposed hard drive)
Purchase your internal drive and kit. Remember that a laptop drive is a 2.5'' drive so you should pay close attention to the size and internal dimensions of the casing when you purchase it to avoid a fiasco later.
Also, when considering your kit, if you are using an IDE drive that you had laying around the house, you need to be sure that you purchase an IDE kit. SATA is the more commonly used method these days, and will not work with IDE. Some kits though, may have what you need to use it either way.
Next, remove the hard drive you either purchased or had as a spare from your computer or its packaging. Connect it to the casing as requested by the kit- plugging in the connector or using the cables provided in the kit. Close the kit around the drive using the screws that are provided in the kit.
Insert the USB cable into the drive, and plug the AC adapter into both the hard drive and the power source. Insert the other end of the USB cable into your computer. You should now be able to pull information from one drive to another.