After you file

No, that doesn't go all the way back to the choices of what changed since the previous year.  It just goes to personal information.  Not far enough to change what I need to change.  I accidently chose that I had started receiving Social Security this year, but I've actually been receiving it for several years. The rest of the return is treating it like it's new this year.  How can I change that? Or maybe it doesn't matter??