Just bought a used Xbox one

Unfortunately the code was likely redeemed by the original owner and is therefore already used.

you don't need to factory reset the xbox to remove his account, you can do it by signing into your account and going into settings>account>remove accounts.

if you can only play by signing into his account then that is breaking the ToU and you could end up with an enforcement action taken against your account and his.

if the person made the xbox his home xbox then you can remove his account from the xbox and play the game on your account.

if you uninstall the game you won't be able to download it again unless you buy it on your account.

I hope this helps

As the code for the game has likely already been used (and if it's on the console it has been!) then no it would not be possible to do this.

Pro tip :- before installing new games go to settings > network > click go offline . Insert disc , install . Once installed go to settings > network > click go online . Install updates once prompted . So much quicker .

You can start a DL or install a game and then turn the controller off .

Go own git!