Replacing a hard drive in a laptop looks easy, but one has to consider that many laptops are designed with a specific hdd in mind, and simply replacing a small capacity one for one with higher capacity isn't always a good idea. The larger capacity drive is more than likely to run significantly hotter and may require a level of cooling that isn't provided within the current case.
So great care should be taken when changing laptop hard drives, and the person doing the changes should soak test it doing something challenging in both CPU and hard drive accessing before handing it back to the end user.
Plus, no matter how much money you spend, don't put a laptop on your lap. Expensive Sony's started going phut and catching fire, with overheating faulty batteries not too many years ago. Some of these were 2 or 3 years old! The moral being - you never know.
A better description would be portable personal computer or notebook computer.