To remove the lite rust use WD40 or Kriol whichever and LIGHLY rub it out with 0000 steel wool or even a rag an the tip of your finger.
For the heavy rust use our search function and look for Electrolysis. There was a good discussion alittle while ago on the subject.
Unfortunately you will have speckling left when the rust is removed .
The cleaning kit in the stock is a nice bonus....