Laboratory grade hexane is expensive but if you catch yourself in a chem lab at some point interning as an undergrad or in grad school then you can try this out.
Hexane is really volatile. I can't stress enough how important it is to keep the work area very very well ventilated. All windows open and a fan or two especially if you have over 1 liter of the chemical.
The following process was done to just the leaves and stems of the plant.
The leaves were put into a blender. Qualitatively, it should be the size of a grain of sand, salt, etc.
The stems were halved and then quartered.
The stems and leaves were then placed in the hexane over night in COVERED container AWAY FROM HEAT AND LIGHT. Make sure the area is nice and cool. Make sure that you put enough hexane to cover all of the plant. Every couple of hours just mix it with a spoon or fork.
The following day, using a strainer, remove the leaves and stems from the hexane and just throw it away or you can burn it outside.
Hexanes melting point is -69 degrees Celsius so you can just allow it to evaporate.
To speed up the process you can boil the hexane as well. Its boiling point is low so not much temperature is needed. You can put the stove top, ONLY IF ITS ELECTRIC, to either low or the first setting. My stove ranges from 1 - 12 and I had it on 2. Put water into one pot and onto the stove. Put the hexane into another pot and place that inside the water. The hexane will boil and bubble and the residue will start to collect on the sides and bottom. Keep the pot with the hexane slightly tilted to allow it all to collect together. Make sure not to go above 66 degrees C or this will break the THC down.
I've read on wikipedia about using butane. Same concept. If you want to make some so-so good hash you can use acetone. Wouldn't recommend it because I don't know what else is in it.