Your personal Facebook account is the key to your business on Facebook. In order to allow someone else to manage your Pages you must grant them admin access.

Facebook Page Access

Step 1: 

First go to the URL of your Facebook Page while logged in. In the second top menu click on Settings. 

Step 2:

On the left hand menu choose “Page Roles.” 

Step 3:

Midway down the page enter the email of the account manager you are granting access to.