Option 1: Break garlic into cloves. Put all the cloves in warm water for 5 to 10 minutes. Then you can easily peel each clove.
Option 2: Hammer each garlic clove with the back of a cooking knife, then you can easily peel off each clove.
Option 3: If you have a lot of garlic that needs to be peeled, put all the garlic cloves in a stainless steel bowl or container, and cover it with the same sized one. Shake the two bowls or containers hard for about 5 minutes. Then open them and you will find most of the cloves are peeled off.