Wis. Stat. § 181.1150

A cooperative or an unincorporated cooperative association organized without capital stock may elect to convert itself to a corporation by adopting and filing restated articles of incorporation or organization in the manner required under ch. 185 or 193. The restated articles of incorporation or organization shall conform to the requirements of s. 181.0202 and shall contain a statement that the cooperative or unincorporated cooperative association elects to convert itself to a corporation subject to this chapter. The election to become a corporation subject to this chapter is effective upon the filing of the restated articles of incorporation or organization.