First of all AccuBook has to "Like" the page that they want to get admin access to.
Please Note: The Page has to be a "Fan Page" not a "Friend Page" in order to add the Booking Engine to it.
Log on to your Facebook account and go to the Fan Page itself. The "Admin Panel" should show at the top of your page.
Simply Click on the drop down on "Edit Page" and click on "Manage Admin Roles" (see below)
Then you will see the screen below. Type the email address firstname.lastname@example.org into the box that the arrow is pointing at in the screenshot below. Change "Content Creator" to "Manager" and then hit the "Enter/Return" button on your keyboard once you have typed the email address and changed the Content Creator Role.
You will then be asked to enter your own Facebook account password to confirm this (see below)
You should now see the screen below showing AccuBook as admin of the page. You can let us know then when you have this done.