Hi FrancoWide,

Most of the gateway products as got their own default Wi-Fi Name and Password which will be located at the bottom/side of the gateway.

It looks like you want to “Reset” the Wi-Fi Key.

Reset is done when our customer forgets their Wi-Fi Customized password so in that case we recommend going for a “Reset” where it will automatically go for the default name and password, so customers can easily sign in.

To do a Reset click on the below link:

http://arris.force.com/consumers/articles/General_FAQs/SBG8300-Factory-Reset

Also, do mention the product's model number so we can provide the appropriate Reset link. 

Let us know if this helps.