If you take the wheel off, the brake mechanism will fall out into your hand. Then you can inspect and clean it and replace the shoes if necessary. This is the safest way to do it as riding on warn shoes will destroy the drum. Very expensive. Try to find someone who has worke on drum brakes to help you. Small amounts of correct lubricant in the right places makes a big difference to operation. Too much lube may get on the shoes and screw up the brakes.