Click the Campus Configuration icon on the left and select the ministry you want to change.

This will take you to your Ministry's High-Access list.

Make sure your campus is selected as the location (1) and click the "+" (2) to add someone to the list.

Search for the name of the person you'd like to add, click the circle next to their name and then click Select.

Select the Role (volunteer for volunteers and staff for staff). Click Save and you're done.