We have followed Ivar's route several times now. We took the 11.00am bus to Lugo - make sure which one you take as 2 left together when we did it. One is direct and the other winds around more villages. We bought the tickets in the bus station. After sightseeing and a night in Lugo we then took the morning bus again to Ribadeo. Most days you get the ticket in the bus station but sometimes on the bus and the times given were not always correct so it is good to arrive about 10 to 15 minutes before the bus is due to leave Lugo. The bus station in Ribadeo is on teh outskirts of town and with easy access to the Camino. As you approach Ribadeo do watch out for the motorway sign 'No donkey carts' with a symbol.
Wish we had been able to find it again to take a photo.