I’m not familiar with the urJTAG package, but as a general rule, if MacPorts instructions are available, there’s not likely to be an easier way. (The whole point of MacPorts is that someone else has already done the work to figure out what it takes to get the package running on the Mac, so you don’t have to. People rarely create a MacPorts package (or whatever it’s called) if the software has a native Mac port.)