Your 3.0 mm nut driver may be too long to thread the hex head screw in. Use one of the following techniques to begin threading the screw in:

Thread the screw in using your fingertips.

Thread the screw in using blunt nose tweezers.

Use your T3 Torx driver to install the 1.4 mm screw into the hex head screw. Then, install the hex head screw using the T3 Torx driver. Finally, hold the hex head screw while you remove the 1.4 mm screw.

Once the hex head screw is threaded in a few turns, tighten it using your nut driver.