You can remove access from people to your company dashboard simply by removing them from your connections. When you have removed the user from your user list, they no longer have access to your company. If you want to give them access again, you will need to send them a new invitation.
How to delete a user:
Navigate to settings > connections
Find the user you want to remove (scroll the list or search with name or email)
Click on the 3 dots next to the user on the right-hand side
Click Remove Access
Confirm your selection by clicking "Remove access" on the pop-up window.
You can also change the role of a user if needed. Read more here.