I tried the following post:
and was able to use Odin to flash CWM and then get SuperSU. SuperSu said it disabled Knox, but when I checked (Vol-+Home+Pwr) knox has been tripped. Oh well.
I also got really thrown off by one part of the above instructions, to enter CWM after you flash it with Odin you need to press Vol++Home+Pwr not volume down.