Seems unlikely that removing the end cap will be easy, especially with the hub laced up into a wheel. From
this VSalon post I quote:
Yes, there is a special Phil Wood bearing press that you need. The axle + bearings are all one assembly and press in and out with the tool. Not too hard once you've done it a few times and learn the tricks to doing it correctly.
Needless to say, I do not have said bearing press. I'm not sure what it looks like, but I wouldn't be surprised if it required the hub to be unlaced from the rim and for the freewheel to be removed first. I'd then be in a chicken-and-egg situation. I suspect the correct solution will be to find a suitable freewheel remover, such as the Dura-Ace or Bicycle Research tools mentioned in earlier posts.