How do you Remove surface rust on nails?

Wire brush. The best thing is a chemical from Loctite, Extend® Rust Treatment,One-step rust treatment goes on white and converts rust to a durable, black, metal-protective coating in 10 minutes. Surface rust must be present. Use as a primer or finish coat. Resists temperatures to 250°F intermittent, 200°F continuous.

You don't have too remove rust (only lose scale)