Are you saying you don't know the User ID and/or password and can't log into the account used to prepare the 2016 return? If that's your situation, we can hopefully help you find the account, so you can get the *.tax2016 data file necessary to amend the return.
Once you get the *.tax2016 data file, you can amend it in the free 2016 software we can tell you how to get. But you need to get the data file first.
