The installation process is not covered in the user guide and I wanted to provide some clarification.
The VM player requirement is a little confusing. While the user's guide is being updated, this blog can provide some insight into the install process.
The Migration Tool is distributed as a VMWare Virtual Machine.
Inside the tgz file you downloaded there is a VMWare VM you can run using VMWare Player. This is available at https://my.vmware.com/web/vmware/free#desktop_end_user_computing/vmware_player/7_0), VMWare Workstation, VMWare Fusion or on any VMWare product that can run on your desktop.
Once you have unpacked the tgz file you can just import the VM into the VMWare product and launch it.