IRS Form 1040X instructions (2017) -<a rel="nofollow" target="_blank" href="https://www.irs.gov/pub/irs-pdf/i1040x.pdf">https://www.irs.gov/pub/irs-pdf/i1040x.pdf</a>
First you should NOT amend a return until you get the original refund or pay the original balance due ... and since the 1040X will take 16 weeks or more to process I don't really see what is the big rush.... patience is needed this year due to all the turmoil at the IRS ... they are way behind in many things this year.
It's pretty straightforward. Follow the "Instructions for Form 1040X".
You must have a copy of your original return.