What is the ruling on excommunicating innovators (ahl al-bidʻah)? Thank you.

"Whoever among the innovators falls into what necessitates disbelief, such as declaring the Companions to be disbelievers, or claiming the creation or distortion of the Qur'an, or denying Allah's attributes, or committing polytheism by invoking the dead and seeking their aid, then it is permissible to rule him a disbeliever. However, whoever's innovation is limited to matters that do not necessitate disbelief, or merely prefers some Companions over others, then he is not ruled a disbeliever."