If your Phil hub is like mine of the same era, and I’d assume it is, you ought to be able to wiggle that axle extension off, then you can get the freewheel tool on. Might require a wrench or pair of pliers (put a rag on the extension to protect it). I was kinda taken aback at the axle parts simply being pressed on (later iterations are threaded), but the hub I have had done a couple decades duty on a tandem without problem before it came to me.