Consider that we defined a web service:

MyServicePortType service = new MyServiceService().getMyServicePortType();

Normally, we would go on and put the param at the service. Not yet, change the address first:

BindingProvider bindingProvider = (BindingProvider) service;

bindingProvider.getRequestContext().put(
  BindingProvider.ENDPOINT_ADDRESS_PROPERTY,
  "http://new.server/endpoint"
);

SOURCE: stackoverflow

Now, do other thing as usual.