You need a machine called "kazan" to make Rakija. Plums are kept in large barrels until fermentation (a lot of midges around the barrel and then appearrance of alchohol).
Here is a picture of the machine kazan:
http://i58.tinypic.com/30ab783.jpg
One part of the kazan is for the fire, in second part to put the water and third part to put fermented plums or some other fruits for example pears...
It is not an easy job, it's an all-day process.