Basically you get some water and use sodium hydroxide to raise the PH level, then you add the mimosa root bark and mix.
After a couple of hours you add the petroleum distillate and mix some more, this transfers the dmt from the water to the naphta.
You will then separate the petroleum from the water and let it evaporate leaving only the dmt, or you can put it in the freezer overnight (this will make the dmt sink in the naphta and is called freeze precipitate).