A family member and I would like to trade our MacBooks with Yosemite installed (one is a Pro and one is an Air). We also have Time Machine backups. What's the best way to do this trade in terms of transferring accounts/files? Ideally we don't want the other person's stuff remaining on the hard drives. Option 1: Create a new administrator account and then delete the current account. Option 2: Create a boot installer USB drive and then do a fresh install. Any suggestions?