To clarify, I e-filed 2019 return through TT. I want to make a edit to SchD that is not supported by TT. Therefore, I assume I will need to manually mail the amended return. I am thinking that I can still use TT to get me started on the amended return and then print out the 1040X and Sch D, which I would then manually complete. I was wondering if anyone had any suggestions on a good method to go about doing this. Thank you.
Yes, when you download the 2019 TurboTax product you are going to get the desktop version (Online for 2019 is not available).
You will be able to make your initial changes through the entry screens. but you will also be able to use the FORMS feature in the top right corner to view and change the forms.
Be aware that if you make direct entries into the forms mode it will void the TurboTax guarantee. I don't think that is your concern right now.