Possible Clues:

• Obvious course of action
• Head introduces Rilke, a simple task
• Hardly rocket science, underwear lacking rein for adjustment
• Trivial matter head doesn't need to be bothered with
• Straightforward choice
• Head in rare confusion - this shouldn't cause it!
• Head back, returning around home, which is easy
• Aristocrat, one of April's eight, far from rocket science
• Nut rare in crumbly piece of cake
• Aristocrat finding Rilke an easy job