1) Edit the post. Select the text and copy. Create new page, paste. Delete post. 🙂
2) How do you feel about direct database editing?
If you’re comfy with phpMyAdmin, or something similar, you could probably do it pretty easily. Posts and pages are both in wp_posts table. If you find the post you’re after in there and change post_status from “publish” to “static” and perhaps give it a prettier post_name (aka title and for posts is usually a slug) you probably got it done.
Disclaimer: just guessing at option 2 based on some db crawling I was doing recently.
3) Collect the ID# of the post you want to switch to a Page. Next, go to Manage > Pages and click edit for a Page (any one will do). For this next part you’ll need to have your browser’s url/address box displayed: Change the url from
POSTID being the ID# for your post. Click Go/Load/whatever to load the post in the Page editor. Finally, save the *Page*.