In order to remove the user, you have to be logged in as a user with Admin permissions. Then you'll be able to deactivate and remove a particular user.
See below for details.
- Go to Users management page

- Click Deactivate link to deactivate the user
Deactivated user is not able to log in but his account still exists and Presentations belonging to him are not removed

- As soon as User account is deactivated you can activate it again or remove completely.
There has to be at least one user with Admin permissions within the Company account!

If you choose to remove user then you have to select new owner of the presentations and other contents (e.g. Tags or ORBITTOUR Templates) of the removed user.

The user account will be removed and all the contents from this user will be moved to the new owner.