In what way better performance?
Faster Broadband - probably not.
More powerful WiFi - almost certainly.
Yes there is, and if you type ‘Netgear router’ in the Search box at the top of this page, you can see all sorts of helpful (and even some successful) description of how to do this.
The most recent posts, and ones that pertain to your exact model of router, or a closely similar one, may give you the best chance of success.
The shortcomings of the NowTV router in this area are well known, and two Ethernet ports is a bit mizzy, so I don’t blame you for looking, but this doesn’t have to be a reason to switch from NowTV Broadband, if you are otherwise satisfied with their service,