To edit and delete users, simply click 'Settings'.
Once you're in the Settings section, under the ‘Users and Teams’ category click 'Users'.
When you click the user you wish to edit, you should see a page that looks like this:
Editing a user's details
To edit a user, click on their name on the right and from there you can edit the following:
Name and email
Set up email signatures (Paste in HTML)
Set which email notifications they should receive
Once you’re done, click the green ‘Save Changes’ button at the bottom.
Once you're on the page listing all your users, click on their name. At the bottom of the page, there's a red 'Delete' button.