this is called tincture.
The method I saw uses 180 proof.
You want to get a smaller bottle like a half pint.
Then you just drink some or pour some out (just a little to allow space for bud)
You then put the bud in the bottle.
You want to keep it in a dark place for about 2 weeks.
You should shake the bottle vigourously atleast once a day.

After two weeks the thc will have worked it's way into the alcohol which has become a solvent in the mixture.

Depending on how much bud and the quality it should be pretty damn potent after 2 weeks.