You cannot change a screenshot image after sending it, that is not allowed, you can delete it and upload the new one. see https://pdfedit.pro/ for a better edit

I found a folder in my home folder called downloads from PDF, so use https://pdfedit.pro/pdf-to-word for reader PDF

These are web applications that allow real-time editing and previews of client-side codes: HTML, CSS, and JavaScript. The best part of these coding playgrounds is that most of them are free and you can easily share a “playground” with someone either for teaching purposes or for debugging, so https://pdfedit.pro/pdf-to-jpg however In the Swift Playgrounds app on Mac, click Run My Code (or use the Touch Bar). If there are instructions on the right side of the screen, they slide down when you click Run My Code, so you can watch your code run in the live view

Maybe you can use https://pdfedit.pro/word-to-pdf for save PDF