If you correctly amend your return (which is not possible at the time of this post for a 2017 return) then when you print it, mailing instructions are printed with it. Sign both the 1040 and 1040X and then mail it to the address specified in the instructions. Where you mail it, depends on what area of the country you are in.
So at this point if you have made any changes to your already e-filed and accepted 2017 tax return, you need to change it back to match *exactly* what you originally e-filed with the IRS. If you do not do this, then when you do amend you will have major issues with the IRS.
