While you are on the site, in your browser find and click "Add to Home Screen" A CGN beaver app icon will then be created to your phone that is directly link to the site.
Note: This feature may not be available in some browsers.
I can't see the sights with great detail from here , but if they are a dovetail sight, use a brass or nylon punch with a hammer. Remember to move the rear sight in the direction you want the point of impact to go.