Quotes from AAW, The New AAW, and SLC.  The names are changed just a little.

SS36:  Is there any spell to change me into a skunk?? I would really love to be one 

Eris:  This is your lucky night, I'm in a good mood.
 
Yes there is a spell. You're a week late though so you'll need to perform this on the next full moon.
 
Forego bathing from here on out. No showers, no baths, no shampoo or any other personal hygene. When the full moon arrives you must head out into the skunks natural habitat and find one. Ask it to show you the way to live life as a skunk. It will need to spray you just as the full moon has reached it's peak, not a moment sooner not a moment later.
 
Once you've basked in the delightfuly fragrant aroma ala Pepe Lepew, get down on all fours and skurry back home. When the family opens the door, they will scream "skunk" and slam it back shut...trust me on this.

Ennove:  Shapeshifting to the extent that you are a skunk, and others see you as being a skunk would be "cost you a lot" I am told.  By legend there are ancient magic people who are dying out who are considered to be very powerful.  By giving them some energy to keep them alive they agree to offer gifts of power.  The gifts and the costs are considered "too expensive" by the contemporary practitioner however.  I don't know how "true" this account is, but I am told there is at least a story about this in one of Castaneda's books, The Art of Dreaming.  The extensive instructions and connections on how to do this is not included if it is true.  I enjoy legends.
 
Becoming a skunk would entail shapeshifting.  People in some traditions can shapeshift to a degree.  Shaman call this dancing in their animal, and somewhere out there your animal is dancing in its person.   

Eris's method probably is the most practical.  I have performed shapeshifting in dreams and in journeys but so far not so well while awake.  Before someone told me how, I was simply trying to become something else.  Now I know the form comes to me, or I meet the form, and a merger occurrs.  It is some sort of Shaman sex  ;) in the way that you merge and actually become each other.

Sanchez, in one of his books about shaminism, brings up shape shifting in this subject chapter:

"Carried to its extreme, the art of pure acting is the art of the sorcerer and the nagual--the art of transformation. What do sorcers experience when converting into crows and flying away? In principle they feel as though they fly, feel themselves as crows, seeing and experiencing the world as such. Their secret is that they are capable of modifying their perceptions to match that of a crow, modifying the position of their assemblage point. Their knowledge of sorcery, their conviction, and their years of work allow them to achieve it. But now we have a question, one that Castaneda put to don Juan long ago: What would a spectator see? An average spectator would probably just see a sleeping person and might think him or her drunk or intoxicated.  But a spectator in a state of non-ordinary awareness or one observing a sorcerer of extraordinary power--one who could force, with the power of his conviction, the movement of the spectator's assemblage point--surely would see a miracle: a person transformed into a crow and flying away. And Castaneda asks the question again: Was that real what I felt? To which don Juan replies, "There is no reality other that that which you felt...reality is a feeling."

From pages 88-89 in "The Teachings of Don Carlos"