We also have a stump......and a stump it will remain!! It was hard enough cutting down, chopping up and disposing of a 25foot conifer no way am I going to spend anymore time and energy attacking the stump.
I wish you luck with whichever method you decide on.
Stump removal people are rather expensive but worth it when it's not doable by your self. Recently on my allotment my neighbouring allotmenteer removed it for me. He is 80 with several health problems - I was so fearful that he may have a heart attack in the process. What a true gentleman and a dear friend now.