1. If you want the deactivated user not to show up in the Boost Dashboard, unassign that user from any cohort they're a member of. This can be done on the Program Admin dashboard. Make sure to save the cohort after you unassign the user. 

2. Go to the Tenant Dashboard and click on the User Admin tab. Find the user and click on their name. After you click on the "More" button, you’ll see a "Deactivate" option in red. Click on Deactivate and hold it down until the red line appears and you see a notification at the top of your screen that the user has been updated.