How do I turn off the missed callers on a Polycom VVX410 phone

No the missed call counts on the top right of the phone. This is a retail environment and there is no need to count missed callers on every phone.

There's not a way to completely disable the notification.  You can only clear the list, but when there's a new missed call, the notification will appear again. 

To remove all calls from the list: 
1. From Home view, select Directories and select Recent Calls. 
2. Press Clear. 

I suggested a new feature on the community to address this issue.  Perhaps you can vote on it?  I have the same issue on call center phones.  Not just this type but on all of the polycoms we have.  https://community.ringcentral.com/ringcentral/topics/options-to-remove-the-missed-call-notifications...

I see your point, it is frustrating to call support then they ask me if i've suggested it on the board. The thing is if i'm calling support i have a problem now and i cant afford to "open a case" or "suggest it on the community board". On the other hand, RingCentral has addressed issues and gotten added or resolved or had a work around to help accommodate the issues people encounter. They've added features that have been requested by the board. I can speak from experience that after having an issue with glip, i was contacted and had my issue addressed and it was fixed in the next update of the app. So while every simple feature may not be on the platform the company does check this board and has dealt with issues that i've come across. 

Are you referring to the red light? You want it off permanently?