If you own a facebook page and you want to add new admin or more than one admin to it in order to help you managing the page or posting status, here are four steps you can add a new admin:
STEP 1: At the top right of your facebook page, click on Edit Page and select Admin Roles from the drop-down list.
STEP 3: To confirm the addition click on the Save button, enter your acoount password and click on Confirm.
STEP 4: Finally and to save the the changes just click on Save., now the new admin has been successfully added, you can add other admins to your page following the same steps
NOTE: You can only add your friends or people who already liked your page as an admin.
I hope you find this article helpful for you.