Western Digital External Hd How Do I Reformat My Western Digital External Hard Drive?

How do I reformat my western digital external hard drive? - western digital external hd

I want to reformat my external hard drive, but have no idea how. It is a Western Digital My Book Essential Edition 1 TB. The problem was when transferring my movies, because after a certain amount, which said that its protected or in use, but if I go back to the device allows me to continue there, where I've stopped, only problem is still there I heard that if you format that could solve the problem.