I downloaded the file wr740nv4_webrevert.rar and uploaded it via the GUI upgrade panel in the router and after waiting for 15-20 mins, I got a message saying upgrade failed.
Next I extracted the bin file from the .RAR file wr740nv4_webrevert.bin and tried upgrading with that and still nothing happened. Once I got a message saying upgrade successful, but after the router rebooted, I found it was running on the same DD-WRT firmware.
So please advise on how to revert back to the stock firmware successfully