WEREWOLF! How exactly can I voluntarily become a werewolf. 
Stupid typos.
In werewolf folklore most people who became werewolves did so deliberately and voluntarily. One of the most common methods is a pact with Satan, so you may want to give the matter some thought first.
In many folktales the werewolf transforms from human to wolf with the help of either a magic wolfskin or a magic ointment, but it’s not clear how one might get ahold of such items other than by the aforementioned pact with Satan or stealing them from an existing werewolf. Some werewolves were said to have been cursed with their condition either because of their sinful behavior or because they ticked off the wrong people. But that’s not really voluntary, although I guess if you knew someone with the power to curse others with werewolfism you could keep bothering them until they did it to you.
The idea that a werewolf can make other werewolves by biting people is quite recent, and was apparently borrowed from vampire lore.
Take your pick, as the following methods have been described in various cultures stretching back quite a ways in time:
Be conceived during Advent or on Christmas Eve.
Be born into a family that is cursed with werewolfism.
Drink water from the paw print of a wolf (just to be sure, I’d say it would be ideal to drink the water by lapping it up while on all fours like a wolf as well).
Eat the brains of a wolf.
Piss off a saint, a witch, or a god and hope that they give you the werewolf curse, but be advised that often the curse is more of the long-term poof you’re a wolf and can’t change back without the one who cursed you granting you release from the curse. If you still want to try this method, I recommend taunting the aforementioned saint, witch or god and then saying, “Do whatever you want to me, you silly goose…but please, PLEASE don’t turn me into a wolf! ANYTHING but that!”
Sleep naked outdoors under the full moon.
Have sex with a wolf. No notes on whether it matters if you literally do it “doggy style” though.
Make, steal, or be given a magic wolfskin girdle and put it on. In some cases you also need a magic salve or ointment and rub that all over yourself first. Recipes for this ointment can be found online or in various books on the occult, but be warned; some of them call for the fat of a freshly killed animal or even a baby, along with various psychotropic herbs and such. Also with this method, it is sometimes necessary to recite an incantation or two, which can also be found online or in various books.
Make a pact with Satan, a demon, or some other powerful supernatural entity to gain the ability to turn into a wolf. Very often this leads to the wolfskin girdle situation described above.
Perform a ritual designed to send your spirit into the body of a wolf; this method of course doesn’t physically change the practitioner, but it does put your consciousness into a wolf body for a while.
Meditate on achieving “spiritual shifting” which would be kind of like the stepchild of the previous method, in that you don’t physically change but try to bring your mind into a wilder, more primal state of consciousness.
Be a skinwalker. See various Navajo traditions for methods of becoming one, though honestly I haven’t seen any detailed descriptions online. I do know it involves an extensive ritual and special conditions must be met to undergo the training.
I can’t tell you how I know this but… this does not work.
Even a man who is pure of heart and says his prayers at night
can become a wolf when the wolfbane blooms
and the Autumn moon shines bright
Does that mean he only becomes a wolf at the end of the year?
I did read a book once that made werewolves immortal, and that was part of the entire point of the curse.
It was also kind of silly, in many ways, now that I think of it. For one thing, the “protagonist” werewolf was an ancient priest cursed by equally ancient god Ahura Mazda. He was Barabbas in the Bible, and in turn cursed Pointus Pilate’s wife. The epilogue fast-forwarded to a sci-fi future.
Yeah, it was pretty silly.