Married couple, each filed 2017 MFS, spouse got her refund, husband paid a lot, divorcing in Dec 2018, both agreed in mediation to amend 2017 to MFJ so husband may recoup some tax as spouse keeps her refund. I expect to amend HIS 1040 (more complex). I expect there's no filing action required relating to spouse original. Any specific recommendations as to the "Explanation of Changes" on 1040X other than the obvious.
ty.