There are a different ways to do the ethanol extraction, mine is basically a combination of two.
First you take a pyrex measuring cup or similar and put your finely ground mushrooms in it. Then you pour in ethanol and let it sit for 12 hours in the dark. I use 160 proof vodka. You can probably use anything over 140 proof, as long as it's not denatured. Be sure to pour in some extra as the mushroom matter is going to expand a little bit. Also, cover (preferably seal) the dish as it's probably not good for the potency to have a lot of air exchange in there.
The second step only involves the mushroom matter after you've strained and put aside the ethanol from the 12 hour soak. Get a pot full of boiling water and make a double boiler with a new dish that you'll use to do a second pull on the mushroom porridge. Add the solids in the dish and combine with ethanol just as before. Only now instead of waiting for 12 hours you'll be heating the ethanol for 20 minutes or so. The water doesn't have to boil, but it should remain hot enough to get the ethanol to boil. Filter out solids while hot and combine the liquids.
If you wish, there's a third step to compact or even get the extract to fit in a couple of gelatine capsules. It involves using the double boiler setup again to evaporate ethanol from the final product at a vastly increased speed. Just do not completely dry it out, I guess.
You can also store it pretty well. It should last for months if not years in the fridge.