Hi! Here's how;
Open the Helix Fi app on a mobile
Go to the ''connection'' menu at the bottom
Press your network's name at the top
On the top right, press on modify (or the little pen icon)
Check ''use different names for the 2.4 ghz and 5ghz network''
Change the 5Ghz's name
press on ''Apply''
Please note that this option will not be visible if you have pods. If you do, you'll have to make the app forget the pod(s) first, separate the networks, connect your bulbs, then go uncheck ''use different names for the 2.4 ghz and 5ghz network'', apply, and then reconfigure the pod.