You can't. Sch-M is a schema modification lock. Blocks everything and is blocked by absolutely anything, including the Sch-S locks that all queries have to take. Online index rebuilds only require short-lived Sch-M locks, so shouldn't be a major issue.

Oh, and you might want to ditch those nolock hints.... See - http://blogs.msdn.com/b/davidlean/archive/2009/04/06/sql-server-nolock-hint-other-poor-ideas.aspx