How to apply of Istighfar?

The hadith, > "O people, repent to Allah and seek His forgiveness, for I repent to Him a hundred times a day." (see for example in Sahih Muslim ) Is it repetitively saying 100 times like "astaghfirlLah, astaghfirlLah, astarghfirlLah x 100 times consecutively? Or is it meant to be, 1 istighfar is like how you would seek an apology to a person? For eg. Hey John, im really sorry for the mistake i did (with genuine remorse in the heart) = 1 istighfar