tax return for I485

Hello:

I am planning to submit I485 (based on EB1 or NIW). Should I submit three years' tax return and W2 at the same time? I took Earned Income Credit (EIC) $246 at 2003 because I have a US kid, shall I report it as receiving public assistance on part 3 line 2 in 485? I am little worry about it. I am thinking to fill 1040X and return this money back to IRS. Do you think if it better for my greencard?
Many thanks for your kind suggestions and input.