Global Truss Wheel for Floor Plate

I've tried everything from socket wrench, open wrench to pliers as recommended by Thomann and Global Truss after sales rep. I even tried to put the nuts and bolts upside down. Nothing worked. I'm a big fan and frequent customer of global truss products but this wheel is near impossible to assemble. The other comment (in german) manage to do it, but what about disassembly for transportation. It's not a professional grade product at all. I've finally decided to send the product back.