Refreshing an imported wadl that has been changed

SoapUI 5.5.0 free version
I started off  via New REST Project, using a .wadl file created from browser output from this:
   https://10.0.100.28:8443/v1/application.wadl?detail=true
I then wrote a large number of tests.
The interface is now changed, some new endpoints, some changed ones, and some deleted.  So I need to refresh the wadl.
But there doesn't seem to be a way to do this.     

I can add the new wadl,  but then I have to rewrite all the (100+) tests over to work with it.
I also tried using the url  above in place of the wadl file created from it, but that doesn't work  (no endpoints imported; see screenshot).
Any suggestions?   Seems like a pretty fundamantal requuirement, surely this must be possible?
Thanks.