In order to manage team members (Invite/Remove) as an admin, you need to go to Connections>Team from the navigation bar.

You will see and can manage all of your team members from there. You can manage Updates Access for any of the member and can invite or remove them (screenshot below)

In order to change admin rights or add a new admin, please reach out to your point of contact or email us at support@investory.io and we will add/change it for you.