how to reset root password

• How to reset ESXi 5.x root password 

https://www.youtube.com/watch?v=Nehxe8j9lgg

• Ubuntu 12.04, 14.04, 15.10 - Forgot Login Password? Change/Create New One. 

https://www.youtube.com/watch?v=qGpvCZO2oOc

• Changing a forgotten root password on an ESX/ESXi host (1317898)

This article provides steps to reset a lost or forgotten root password of an ESX/ESXi host.If you have forgotten or do not know the password for the root user on an ESX host, you may be able to change it without reinstalling.Reinstalling the ESXi host is the only supported way to reset a password on ESXi.ESXi does not have a service console and as such traditional Linux methods of resetting a password, such as single-user mode.
https://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1317898

• Alternate Root Shell Method 

All it takes is adjusting the boot parameters slightly and typing a command or two,
http://www.howtogeek.com/howto/linux/reset-your-forgotten-ubuntu-password-in-2-minutes-or-less

• Linux İşletim Sistemlerinde “root” Parolası Sıfırlama Yapılandırması

http://www.koraykey.com/?p=4988