I have a 1 tb WD external harddrive for my Mac. I just purchased a new Mac and would like to clean out the wd external hardrive and start fresh with my new mac. Can someone tell me how to do that? I have disconnected the HD from my new mac because when I pluged it in to the new mac it just sat on the table banging around loudly. Do I need to buy a new hd and start over again? The one I have is barely over a year old.