R6260 Firmware reinstall

After turning it on my router's power light perpetually blinks green and stopped working completely. After doing some research it looks like it got bricked during a firmware update. After trying everything, it looks like the solution is to force a firmware install via ethernet and tftp2 app on my laptop which seems to resolve virtually everyones problems that post here...but I cannot for the life of me get it to work.

I've followed the steps exactly but nothing every happens once I press "upgrade" on the tftp2 interface. Here is one of the guides I have been using: https://kb.netgear.com/19841/Reinstall-the-firmware-on-a-router-without-the-setup-CD-recovery-tool

My hardware (router) is under warranty, but apparently since its been >90days since the purchase I can't call in to submit my warranty without paying the $50 phone support fee...which I'm refusing to do out of principle. I have another router I'm using currently but it pretty old and barely getting the job done so I'd like to fix this one soon.

I know this is open-ended but any suggestions?