Office 365: all about managing users on SharePoint Online

GET-SPOUser  Office 365: How to Remove user from SharePoint Online site

SET- SPOUser  Office 365: How to set user as Site collection administrator


ADD-SPOUser Office365: How to add user to SharePoint Online site using PowerShell

REMOVE-SPOUser Office 365: How to Get list of site User/Groups for a site using PowerShell