@SuperSoph_WD, Wcschuyler did not say whether the My Book was an Essentials model (encrypted) or an Elements (not encrypted). That said, a 3TB My Book is configured with a 4KB sector size, in which case removing the drive from its enclosure would expose its native 512e sectoring, rendering the data inaccessible, even if not encrypted.
If Wcschuyler does not wish to preserve the data on the My Book HDD, then it can be repartitioned and reformatted inside the PC as a normal drive. There is nothing special about it in this regard.