If you browse in C:\Windows\System32\ folder, you will come across and .exe file named as tsdiscon.exe. This is the Session Discontinuation Utility.
This process disconnects the current session, and can be used to create a shortcut to switch users in a click.
To do so, Rt click on desktop > New > Shortcut > Type
Click Next > Name it ‘Switch Users’ > Finish.
Give it a suitable icon.