Change User level of a page

Create a new user with author role, then you can bulk edit (when logged in as admin) the pages and assign new user.

I’m not sure I understand the question, but you can designate author in author meta box… If you’re not seeing the meta box in post/page edit screen, click “Screen Options” (top right) and make sure the Author box is checked.

I logged in as an Admin & created the pages, hence they cannot be edited by anyone else but Admin who has the highest level- But I would like to allow ‘Author level’ user to edit it.
Option 1: Is to delete the pages, Login as an Author level user and recreate the pages.
option 2. another way would be to give out my admin passowrd so other members can login as admin and edit the pages.

I do not like both these options. Can I change( downgrade) the user level of the admin created page to ‘Author level’?

I get your point.

You can assign a different author to the posts, using the “Quick Edit” option that is displayed on the posts page (wp-admin/post.php)

You can even change authors in one-go.

Check this video tutorial I created for you: https://screencast.com/t/pGU8FFywI

(This video demonstrates how you can “Bulk edit” authors for multiple posts at once).