is definitely the method to use. That being said, you can take one of two routes:
1) Apiol, Safrole etc. are very soluable in alcohol. You could take the plant material, leaves, berries, etc. and soak in say 97% Isopropyl Alcohol for a few days, strain, then evaporate as much as the alcohol as possible. Take the remaining liquid, and then steam distill that in a relatively small glass setup. The steam distillation will carry the pure essential oils over and in the receiver you'll have a layer of water, and one or more layers of oil. The oil layers will be on top of the H2O or, as in the case of Safrole bearing oil, on the bottom, depending upon the density of the oil. Then seperate the layers in a Sep. funnel. You can further refine the oils gathered by fractional vacuum disttillation. I've used this method to produce almost pure Safrole from Sassafras root bark.
2) You could directly steam distill the plant material. This depends upon what type of steam distillation apparatus you're able to procure or build, and the size of it. Obviously when you have plant material that is relatively low in percentage of oil or compound you desire, the BIGGER the better. You could place the leaves in a drum fitted with a condenser and then feed steam from say, a Pressure cooker, into it. You can also do it in glassware on a smaller scale. I've found that a "vertical" style of still works very well; i.e. where steam is fed from bottom flask into an upper flask of material (check out:
http://www.heartmagic.com/EOflyerNEW72dpi.jpg
for a pic of what I mean) and thence into condenser, etc. Again, you will end up with layer(s) of oil(s) and H2O.
This method produces very high quality of oils and material directly, but on a smaller scale.
The nice thing about Steam Distillation this way is that ONLY volatile organic compounds like Safole, oils, etc. that are immiscible (insoluable) with water will go up and into the steam and be distilled. Any water soluable constituents will mix with the H2O in the biomass flask and then drain back into the steam generator (water) flask. Oils obtained with this method can also be further refined by Fractional/Vacuum Distillation with a Vigreux or packed column.
If they drive God from the earth, we shall shelter Him underground - Dostoevsky