I'm reading about the Senate nuclear option and am a little confused as to how the procedure works. According to Wikipedia:

"The option is invoked when the majority leader raises a point of order that only a simple majority is needed to close debate on certain matters. The presiding officer denies the point of order based on Senate rules, but the ruling of the chair is then appealed and overturned by majority vote, establishing new precedent."

If the presiding officer denies the point of order based on Senate rules (super majority), how is that ruling then overturned by simple majority?