Start of the 33 bus route.

The 33 bus goes from the bus station all the way through the centre of Granada down the Gran Via, past the cathedral etc.
It goes every 15/20 minutes.
To get here you just get on a 33 bus going away from the bus station.
If you get the 33 on the Gran Via the bus stop is the same side as the cathedral.
There is a little supermarket just by the bus stop. It is even open on Sundays.