how do i update my smart wifi netgear 6250 router

https://kb.netgear.com/23960/How-do-I-manually-update-the-firmware-on-my-NETGEAR-router

Netgear has set up a community forum specifically for General Router products. Most of the people who watch that forum are more likely to have experience with older routers and know how to work it better than those of us who follow this router forum. Might be more likely to find someone who has a solution if the question is posted there:
https://community.netgear.com/t5/General-WiFi-Routers-Non/bd-p/home-wifi-routers-general

Please use this link to the main forum product list to review and choose where to make your posts. 
https://community.netgear.com/t5/NETGEAR-Forum/ct-p/en-netgear

Thank you