Use the point edge of a knife and cut through the rind. Make at least three cuts in this manner.
Peel off using your fingers.
I just realized I don't have a picture showing how to cut plantain. There are two was you can cut the plantain, in slices no larger than 1/4" thick or in chunks about an inch in thickness. The picture below shows the thicker plantain. In my country these are called Patacones. Puerto Rican's call these Tostones.
To make the Patacones, after cutting in approximately 1" thickness, you will fry in hot oil (vegetable oil or canola oil). You will need to put more or less 1/4" oil in your frying pan. Cook on each side until the plantain changes color. It will not be cooked through yet. Remove plantain chunks from the oil and mash them. If you don't have a masher like mine you can use a clean brown paper bag. Place plantain in between two sections of paper and mash the plantain.
This is the plantain masher I bought in Panama.
The plantain will look like this after you mash it.
After mashing the plantains, return them to the hot oil to finish the cooking process. You will now just cook them for a couple minutes on each side on the hot oil.
Cooked plantains. Sprinkle sea salt or regular salt once they are cooked.
The ones in chunks are semi cooked. Semi cooking makes it possible to mash the plantains.
The easier method of cooking green plantains is to simply slice and fry in hot oil. They cook very quick so keep an eye. Place hot plantains on paper towels. Sprinkle salt as soon as they are done.
It is best to cook and eat your plantains right away. If you do have left overs you can save in the refrigerator but will have to reheat in the oven or toaster oven to restore the crispiness.
Plantains are good to eat and good for your health too. Read more about the nutritional value of the plantain here