1. First, press Save it for Minecraft in the SkinShow App, and then the skin will be saved to your photo album. (From the system gallery you will find that the skin image is blurry, which is normal, but the skin image will display correctly when loaded into Minecraft.)
2. Open Minecraft PE, and press on the Dressing Room button in the bottom right corner of the screen
3. Press on Edit Character.
4. Press the green hangers button on the left, then press the Owned button.
5. Press the gray man under the Import text, then press Choose New Skin.
6. Next a gallery will open. Find the skin image among your images and select it.
7. Choose the model which looks best for your skin. The difference is the arm sizes.
8. As soon as you open a world you will have your new skin.