Not sure what your problem is , -XM- ?
Any image editor that can load EXR and can save in standard formats (basically all of them nearly) should work.
Did you change the channel mode to 8 bit (mostly for standard formats) ?.
I think without this you will not see the other format options to save .
You may have to make some adjustments before you save ,
because the standard formats do not know in which color space (to say it basically)
to save , or your saved image will not appear as you wanted.