supr3me

Hi, I'm new here I just did full service to my car (60k miles) and I've noticed a leak at the back of a gearbox. Maybe someone can help me to find out what happened. Gearbox oil changed at 40k miles at Audi Hull UK. Do I have to take out whole gearbox or just the back part? What could be the cost to fix it? Do I have to change gearbox oil again? Thanks