Very good question seems like there is a way thank you have learned something new

I would also like to know the answer to that question

Never done that but good to know.
Ed

I did it a few times with plugin as Ian suggests. Deactivate it afterwards. All is preserved.

Very good question WestBay! I had no idea this could even be done!! Well, there's proof you can learn something new just by reading someone else's questions. Thanks!

I used post type switcher same as piofjr. And as IMc said you can deactivate or delete when you are done. I haven't used Convert the page to a post but that sounds good also.

Use a plugin. Convert the page to a post. Then you won't lose your comments.

Don't worry about having an extra plugin. It isn't life and death or an end of days scenario. Just deactivate it once you've used it.

From my own experience it's intact. I used 'post type switcher' plugin. I don't know about how you switch your post to page vice versa.