1. Download this Chrome Extension Tool: https://chrome.google.com/webstore/detail/webp-image-converter/pbcfbdlbkdfobidmdoondbgdfpjolhci
2. Click this jigsaw icon in the top right of you Google Chrome browser:

3. Click the pin icon next to 'WebP image converter':

4. Click the 'WebP image converter' icon in the top right hand corner of your browser:

5. Convert 'webp' to 'jpg':

6. Open your store like a customer (front end) and click on the product you would like to download the images from:

7. Now click the image that you'd like to download: 
8. When the image you want to download is large like below, simply right click on it and choose 'Convert and save image as':

9. Save the image wherever you like.
Tip: repeat steps 7 to 9 to download other images from the same product.