Disk Drill is one of the best mac data recovery software.It helps you undelete Mac OS files using quick or deep scanning.Disk Drill can recover deleteed files from any mountable media like your main hard drive,external hard drive,memory cards etc.This application can recover photos,music,documents and many other unknown formats.
Download and Install Disk Drill.
Connect to the Hard Drive.Start Disk drill in recovery mode.Select the hard drive.
Select scanning method.You can either go on with deep scanning which might take time.
leave the scanning for sometime