Some people on the DTA thread have posted the CAD drawings of the wrench that you can have 3D printed. I just happen to have a friend that printed me one. If you know someone with a 3D printer you search for the post with CAD files.
I messed with the rifle, was able to get a screwdriver inside handguard and lever the ring around. Put some green locktite on it and hopefully it holds. Not paying 95+shipping for a dog leg spanner wrench from DTA.