A laptop's battery inevitably lasts less and less time, so buying a replacement battery eventually becomes a must unless you want to carry the charging cord around with you everywhere. Replacing a battery on a MacBook Pro, though a straightforward process, the specific steps vary across the different models. But yes it is as simple as taking the old on out and putting the new one in. The high quality and new cells means it will hold a charge better than any used battery, meaning you can take it for even longer periods of time without charging it. An affordable alternative to buying another MacBook Pro.