How do I do the student interest part of taxes?

You are NOT allowed to redo your federal tax filing with the same form or electronic filing method as you used originally.

Once you have filed once, the ONLY way to make changes or additions is to use Form 1040X. This form cannot be e-filed and tends to be processed rather slowly. If you complete it properly and send it by U.S. mail, you will receive your refund eventually, but not right away.

Are you asking (1) how to take the student loan interest deduction on your state taxes OR (2) whether you need to file an amended Federal return to claim those expenses on your 1040 because you forgot to?

If (1)...what state are you living & working in? If (2)...see Form 1040X and related instructions.

It's a part of your federal return, a reward for repaying your student loans, you get a deduction for interest paid.

There's a half page worksheet you complete, p.33 1040 instructions booklet, completing it, put amount on L.33 of 1040.