- Select Security > Role
- Click on Page Manager
- Click on Members
- Click Add
- Search for the user by Last Name
- Click the blue arrows to the right of their name to move them to added users
- Click Save & Exit
If you do not want to give a user the Page Manager role, but still want them to be able to edit website content, follow the steps in How can I give a user access to edit certain onMessage site pages?