Open the Instagram app or website
Find the image you want to save
Take a screenshot of the image
Crop the screenshot to keep only the image
If it is your own post, open the post options and use any available download or save feature
If the image is on your device already, save it from your gallery or downloads folder
If you have permission from the owner, use a browser extension or download tool that supports saving images
Respect copyright and privacy before saving or sharing any image