Book the flight:
Wizz Air Eindhoven - Varna or Ryanair Charleroi - Sofia (it's both sunday 27/10 - 3/11/19)
TIP: you can also like this --> IN: Eindhoven - Varna & OUT: Sofia - Charleroi: like this the price is better and better hours (also the leaders booked this)
TIP: book priority to take 10 kg on the plane.
Also possible with your own car to drive to Yambol