Ginger's brown outer peel looks tough, but it's not. It's so thin and light that you don't need a knife or vegetable peeler to peel it.
To start, break or cut off the the amount of ginger you need. Slice off any small protruding limbs to make the main piece easier to peel.
Hold the piece of ginger in one hand. With the tip of a spoon, scrape away the ginger's peel.
You'll be surprised by how little effort it takes to remove it. Because spoon tip is dull, it easily takes off the soft peel without wasting much of the aromatic flesh.
Once you've peeled the ginger, you're ready to prep it further.
Reference: How much is a thumb of ginger? (Cookthink)
Reference: How to mince ginger (Cookthink)