From Runes of Magic Wiki
 Trade Overview
Extraction requires a lot of patience and concentration!
You can find the "Extraction" skill in the "Normal" tab on the "Skill" interface. Then when you are on the Extraction page choose the recipe on the left side. Then, in the lower right part of the interface, select the quantity to be produced. If you have enough materials in your backpack, press "Craft" to begin work! However, you need to be near Alchemy Tools to do this. you can learn extraction recipes from a herbalist instructor.