Can anyone offer a suggestion of how to proceed in this situation?

I lost the password of a laptop with Zorin 16.3 installed. 

As it currently does not ask for password upon start-up, and screen is set to not go to sleep, 

it does not matter short term.

However, it will not update without 'authentication' of the password.

So I decided to re-install and create a new password.

Saved a copy of Zorin 16.3 software and Balena Etcher 'installer' software in a USB flash drive,

but when I started to follow the installation steps the device demands the password to

'authenticate' before proceeding with re-installation.

Suggestions please?

Or, a recommendation for a Auckland repair business for this software and situation?