This article explains how to add and remove users from Hubspot
If you have Add and edit permissions then you can add and remove users in HubSpot. To do this, click on the setting icon in the main navigation bar and go to the Users & Teams tab.
From there you can either use the checkboxes to delete the users or click Create User to add a user. For more information on how to add and remove users or what this entails please view this HubSpot article.