Here's what I can recommend:
* Contact a wildlife removal professional: They are trained and equipped to handle skunks safely and effectively. They can also advise on how to prevent future problems.
* Don't try to trap or remove them yourself: Skunks can spray, which is a very unpleasant experience. They can also be aggressive if they feel threatened.
* Do not use any harmful or toxic substances: This can be dangerous to the skunks and could also pose a risk to other animals and the environment.
Here are some preventative measures you can take:
* Seal up any entry points under your shed: Check for cracks, gaps, and holes, and seal them with caulk or metal mesh.
* Remove potential food sources: Keep your yard clean and tidy, and don't leave pet food or garbage outside.
* Use motion-activated sprinklers: They can deter skunks from coming near your shed.
Remember, it's best to consult a professional to ensure the skunks are dealt with safely and humanely.