Wis. Stat. § 853.54: Revocation or revision.

(1) A Wisconsin basic will or a basic will with trust may be revoked and may be amended in the same manner as other wills.

(2) Any additions to or deletions from the face of the form of the Wisconsin basic will or basic will with trust, other than in accordance with the instructions, shall be ineffective and shall be disregarded.

(3) Notwithstanding sub. (2), any failure to print in the proper places, provide the full name of a person or charity to receive a gift, include residences or use the phrase “not used” where applicable does not affect the validity of a Wisconsin basic will or basic will with trust.