This may be a little easier:
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
/wp-admin/page.php?action=edit&post=PAGEID
to
/wp-admin/page.php?action=edit&post=POSTID
POSTID being the ID# for your post. Click Go/Load/whatever to load the post in the Page editor. Finally, save the *Page*.