Complex sentence: On July 12,2013, YouTube broadcaster Felix Kjellberg, also known as PewDiePie, asked his fans to donate to Charity Water in one of his videos, as a way for him to celebrate the fact that he had over 10 million subscribers on YouTube.
Split into simpler sentences: On July 12,2013, Felix Kjellberg, better known as PewDiePie, asked his fans to donate to Charity Water in one of his videos. It was a way for him to celebrate the fact that he had over 10 million subscribers on YouTube.