- Create a new virtual machine using "Install Windows or another OS from a DVD or image file", click Continue
- Select Mac OS X, click "Customize settings before installation",
- Set the name and location of the VM, click Continue
- Click Hardware, Hard Disk 1, click the [-] button to remove the hard disk
- Click "Move to Trash"
- Click [+], select Hard Disk, Type: Existing image file, choose file path of the new .hdd file. Or create a new image file
- Select a new image file and resize the file system that you want!
Easy, right ?