Need to amend return due to W-2 correction

[ash11]

I had recently e-filed my 2019 tax returns which has been accepted by IRS though I am still waiting to get some refund back. Today I was notified by my employer that I will be receiving a revised w-2.

Changes on W-2

Box 12 code w:  Employer contribution added (missed in the earlier provided W-2)

I understand that I will have to amend my return. I never had to deal with this situation till date.

I would assume TurboTax should make it very convenient. I only need to amend my federal return as there is no state return applicable in my case.

I am looking for some answers in order to make sure I am amending my returns correctly.

• In Turbo Tax once I start the amendment flow in my specific case it should be just updating W-2. I am assuming rest of the earlier information is already there with TurboTax and I don't need to revisit. Is that correct?
• Can the amended tax return not be e-filed?
• If I must mail the forms in my specific case what all forms I need to send to IRS? Does it mean all forms generated by TurboTax including the Form 1040X?

[ash11]

I was able to find the answer for the first two questions.  When I print the amended return to be mailed to IRS i see that TurboTax prints not only the Form 1040X but also all the previous forms and schedules though none of them actually changed. 

Should I not be just mailing only the Form 1040X and the revised W-2 form? Please confirm.