To delete a user from the VIGIE portal, go through the following steps: 

Step 1:  In the main menu, on the left side, click on Users Management. 

Step 2: Select the user you wish to delete. A side window with the user's data will open.

Step 3: At the bottom of the side window, under actions, click Delete User.

Step 4:You will get a warning saying " Are you sure that you want to delete the existing user and it´s settings?" Click on the Yes option. 

Example of how to delete a user: