Steps to Amend my return (filed as Sch C instead of 1065)

I'm confused on how to get started...

Background: using TT Home and Business I filed my 2020 return with a Schedule C, however,  the Sch C business should have been filed as a partnership using Form 1065 on TT Business. 

 

Where do I start, what are the steps?

Do I open TT Business and say amend the Schedule C (even though that form is not on the software)?  Any help is appreciated.