You are correct that starting a new return and simply adding carryovers is the easiest and quickest way. Form 8582 specifically deals with the Passive Activity Loss carryovers, so be sure to have it ready when preparing your 2018 tax return. If you are using TurboTax Online, you would have to create a new account. If you are using TurboTax Desktop/download, you will simply start a new return in your software.
To adjust manually 2017 TurboTax file, you will have to recreate your amendment, and it must match the exact figures prepared by the tax firm you used. It will be a cumbersome process...
