You have two options when you wish to remove a user's access to OnBoard.
Option #1: Removing the User's Membership from your organization
If you would like to keep the user's in your organization but remove that user's access to any of your organization's information (meetings, resources, directory, etc.) You can simply use the permission dropdown next to the user's name and select the Not a Member permission. This will keep the user in your user list in case they ever need to be added back to the organization but removes all of the user's access to organization information.
Option #2: Completely deleting the user from your organization
Your second option is to completely remove the user from your organization. This removes all of user's access. The user will need to be reinvited to the organization if you like to have them rejoin the organization in the future.
To delete the user, first click the Edit button in the top right corner of the User List screen.
From here, simply click the red Delete icon next to any user you'd like to remove. Optionally, you can use the check boxes to the left of any persons name to select more than one user at at time, and then click the Remove button at the top. Click OK to confirm the delete.