VirtualBox command line. Removing innaccessable VMs change machine location

To delete virtual machines from the command line, first I removed the *.vbox *.vmdk files etc (basically the folder that these files are in).

Then;
VBoxManage list vms (this lists virtual machines)
VBoxManage unregistervm ********* (where *** is the number of the VM as shown by the previous command).

To change default location of VM's
vboxmanage setproperty machinefolder /path/to/directory/
Note use path in quotation marks if folder needs a space, example;
vboxmanage setproperty machinefolder "/var/VirtualBox VMs"