I0.3 does not include the Mac front-end that 10.2 was packaged with... and 10.2 no longer seems to be available. BUT if you still have a copy of 10.2 on hand you can hack it to install 10.3, like so:
Open the 10.2 package. Open the Resources folder. Open the Java folder. Replace 1.10.2.jar with 1.10.3.jar. Next, go back to the Resources folder and copy in the lib, manual and themes folders. For good measure, copy in the .bmp and .png files. Finally, go back up to the Contents folder and edit the Info.plist file, replacing the one instance of "1.10.2" with "1.10.3". Close. So far this seems to work (for me). YMMV.
I have no idea why the Mac front end was dropped, (and the release notes make no mention of it's passing) except, perhaps, that it's a little hard to run it from the command line when it's buried deep in the front-end package.