Apply heat and use a quality 2.5mm hex driver, I put the bottom of the chassis directly on a table for maximum torque transfer. Variation in tires/suspension when unloading and loading that clamp will most certainly end up in a stripped hex. If you already stripped it, tap in a 7/64" hex or dremel a slot for flathead screwdriver. Again, the factory uses threadlock so heat is your friend.
Apply heat and use a quality 2.5mm hex driver, I put the bottom of the chassis directly on a table for maximum torque transfer. Variation in tires/suspension when unloading and loading that clamp will most certainly end up in a stripped hex. If you already stripped it, tap in a 7/64" hex or dremel a slot for flathead screwdriver. Again, the factory uses threadlock so heat is your friend.