Get the car up on ramps. You may need to remove the small jacking plate (4 bolts, 2 nuts).
Just use a short 12mm wrench. There are four lines with nuts exposed. I've posted a pick before.
BE VERY GENTLE. Don't overtighten.
My first car had a line fall off, I know 3 or 4 people locally affected.
On my new car and TT_TTF's car we both had loose fittings which I tightened. It isn't much, basically about 1/8 of a turn to take em up.
But given vibration, the pressure they're under, they eventually do "undo".