We recommend that you start from scratch end reenter everything manually. If the deceased spouse was listed second on the 2015 joint return, it's very difficult to cleanly remove all the spouse's information. You're likely to end up with mysterious errors in the 2016 return that are very difficult to correct, or that might not be apparent. If the deceased spouse was listed first on the 2015 return, for all practical purposes it's impossible to remove that spouse and end up with a valid return. Attempting to switch the order of the names will cause problems, too.
