The Smart RG 516n or 506n operates on a frequency: 2.4 Ghz. Here’s how to change the password, in steps.
1 Access the management panel
Follow the method presented in the “How to access the Smart RG Management Panel?” linked at the bottom of this page.
2 5 Ghz network
View the following menu section: Wireless->

Delete the contents of the box “WPA passphrase” and enter the new password.

Click Apply / Save

4 After the change
After saving, the modem will turn off the wireless network (WiFi) and restart it without your intervention. The modem does not need to be rebooted.
Note that if you use the modem’s wireless access (WiFi) to connect to its management panel, you will be unplugged from this panel and the network. Access the wireless network (WiFi) with the new password and access the panel again to make other changes.
5 Reconnect your equipment
Remember to reconnect all your equipment to the wireless network (WiFi) using the new password.
6 In case of problems
If, after changing the password, you no longer have access to the network, start by restarting the modem and check that at least one light is lit on its case. If this does not restore the service, contact our technical service. We can help you restore it.