To export and backup an image from VMware vSphere Hypervisor 6.0, first use the vSphere client and login to the server. As vSphere client only works on windows, you will need to install vSphere client on a windows machine or use virtual box.
To backup,

1. Select the VM you want to backup
2. Select File -> Export -> OVF template
3. Select the local folder you want to store this in
4. Done

You can then convert OVF file via virtualbox cli for spinning up locally, or you can redeploy this somewhere else.