Complex sentence: "Skyscraper" debuted at number ten on the "Billboard" Hot 100, selling 176,000 downloads during the first week of release, becoming Lovato's highest first week sales, until the release of "Heart Attack" by Lovato in 2013.
Split into simpler sentences: Skyscraper debuted at number ten on the "Billboard"Hot 100. It was Lovato's highest first-week sales until the release of "Heart Attack" by Lovato in 2013.