How can I delete demo games from my Xbox account ?

Hello Anton,

Thanks for your reply, and yes just as they have posted above unfortunately there is no way to just "Delete a game" from your account.

Although, you do have the option to Hide/remove from game list, and
uninstall the content from the device.

1.
How to remove a game or program from the My games list

2.
How to uninstall and reinstall a game on Windows 10

Hope this helps.

Once you own the game, you cannot just remove the game from account. You can just uninstall it.

There is currently no way to delete a game from your account. You can highlight the game in question, push start then select hide.

Select the home button on the game you selected and go to manager and add ons. You can unstall the game.

Simply just uninstall the game and it should be removed from your games list and put into ready to install