How to remove rust from car battery contacts

1. Preferable way: WD-40. Drop it to the rusty place. Then be patient, wait for around 10 minutes. The rust will be dissolved.
2. Mix baking soda with water. Then apply it to rusty place. Maybe wait for few minutes to let soda complete its work.
3. Coca-Cola - this drink already contains soda and other chemicals. While they are not good for human health, they dissolve rust.