Here is a simple method of grasping a weasel by the scruff of its neck, hypnotising it, and having it do your bidding.
1. Take one weasel.
2. Grasp the weasel by the scruff of its neck and hold it so that its head is no more than a couple of inches from your eyes.
3. Stare into the eyes of the weasel while making hypnotic weaselly noises.
4. Place the weasel carefully on your floor and issue it with a command.
5. When the weasel returns from its mission, pick it up by the scruff of the neck, and repeat step 3, substituting hypnotic weaselly noises with antihypnotic weaselly noises.
6. Release the weasel.
What could be simpler than that? Indeed, the only difficulty most students find is to think up a suitable command for the hypnotised weasel to obey. Experience shows that tasks involving high-pitched squealing and savagery are likely to achieve the best results. If you are of a squeamish disposition, command the weasel to do its slashing and slaughtering in another room, or even outside, in your front garden, if you have a front garden. Try to remember that weasels will attack most effectively if set upon organisms of equal size, or smaller than themselves, although in certain circumstances they can prove lethal and terrifying pitted against larger beings, particularly if such beings are tethered to a stout post.
Advanced students may wish to attempt the grasping, hypnotising, and commanding of more than one weasel at a time.
Even more advanced students can omit steps 5 and 6, and maintain a pack of hypnotised weasels primed and ready to do their bidding in perpetuity, or until the weasels die.