You just have to amend the 1040. You can use Turbo Tax for the last 3 years. So before that you need to amend by hand or go to a local tax place or accountant. You shouldn’t need to tell Social Security.
How to Amend a prior year
https://ttlc.intuit.com/community/amending/help/how-to-amend-change-or-correct-a-return-you-already-...
