Work Advice: Changing the route to retirement

Reader: There seem to be plenty of articles about taking a strategic step backward in your career when young. But what about when you're near the end of your career, in a large Fortune 500 company? The objective is to try to stay employable (and be happier with the actual work) until retirement. It seems possible to step back one level and take a cut in salary, but would HR entertain that request? Or would even asking have negative consequences?