The department shall acquire by purchase, gift, or condemnation all advertising devices existing on May 21, 1965, which violate the provisions of this chapter or which fail to conform to rules promulgated by the said department under this chapter and all rights and interests of all persons in and to such devices; except that in instances involving any authorized device which fails to conform to rules, the said department shall give notice to the owner of the device and to the owner of the land on which the device is located and shall give the owner and landowner time to conform to such rules as provided in section 306B.5 before proceeding as directed in this section. The provisions of chapters 6A and 6B shall be applicable to any such condemnation and the said department shall have the right to take immediate possession of and remove such devices under the procedures of section 6B.25.