fredobox my dad has been making butter and oil for quite some time now.

I don't make it, but he has explained it to me and I have seen and smelt it being made a lot of times.

His process is as follows!!!
He uses only the clippings from his plant harvest. This amount varies so the amount of butter produced will varies also.

You take the leaves and small stems and grind them up. He uses a blender.
Some leaves are dry and some are still wet it doesn't matter.
Take the ground up material and place in a crock-pot, or slow cooker what ever you call it.
Now experience will help out!!
Put in enough butter or oil to just cover the ground up material. maybe 1/16 of an inch above the material.
Simmer this for a minimum of 4 hours!!!! You need to break down all the plant material to get the good stuff out!!! He has cooked it up to 8 hours depending on the amount he is cooking.
Try to remove as much liquid as you can, then strain the material through cheese cloth or something. Get every drop

I don't really know if this much help, but his products kick ass.
Use this in recipes just as the recipe requires, its unbelievable how baked you will get off 1 TBL of this in brownies.

Disclaimer!!!
He uses great quality clippings!!!
Northern Lights, Skunk/Haze, Pez, Trainwreck, Real McCoy coming soon Thai!!

He will probably chime in when he sees this post!!