How to renew the password from the computer forgot it?

I have the following problem I can't log in to my laptop first time shut down and forgot Zack password! So one knows how to bypass the password so without support services or support software only with the laptop

Only with the laptop you can insert a live Ubuntu CD and change the password. There's no other option.

For the exact procedure you would have to use google as it would be too much to explain that here.

Yes, with the USB stick that has already been created, if available, which has been specially created for this case