If the machine was delivered new to its present location it would have had a steel bracket painted red bolted to the end head and to the table so you might be able to find this somewhere in your shop. There is a threaded hole (3/8"-16 NC) at the bottom of the head behind the spindle nose and it is easy to make something to bolt on here and onto the table. Whatever you use it should be rigid so the axes cannot vibrate. I have simply used a short piece of heavy angle iron bolted to the head and then gripped in a vise.
When the machines are shipped from the factory the flexible holder for wires and hoses at the top of the spindle is also braced by strapping lengths of wood on either side, the doors are held closed with a strap around the handles and the control panel is strapped to the front of the machine with some foam padding between.
Also if it will be transported a long way by truck or train bolting it to a heavy pallet the same as it is shipped on makes it easier to strap it down but this is not essential provided it is secured on a truck so it cannot slide around.
An open mind is a virtue...so long as all the common sense has not leaked out.