In Lightning Experience
1. Click the gear icon.
2. Click Setup.
3. Enter Login Access Policies in the Quick Find box.
4. Enable Administrators Can Log in as Any User.
5. Click Save.
Enable the 'Administrators Can Log in as Any User' Feature help.salesforce.com > apex > HTViewSolution > urlname=Enabling-Organi...
From Setup, enter Users in the Quick Find box, then select Users.
2. Click the Login link next to the username. This link is available only for users who have granted login access to an admin or in orgs where admin can log in as any user.
3. To return to your admin account, select User's Name | Logout.
Enable Log In as Another User - Salesforce Help help.salesforce.com > apex > HTViewHelpDoc > id=sf.logging_in_as_anot...
Option 1 - Open the browser as a different user:
1. Hold 'Shift' and right-click on your browser icon on the Desktop/Windows Start Menu.
2. Select 'Run as different user'.
3. Enter the login credentials of the user you wish to use.
4. Access Cognos with that browser window and you will be logged in as that user.
How do I login as a different user when Active Directory SSO - IBM www.ibm.com > support > pages > how-do-i-login-different-user-when-act...