Don't go cheap with the stump grinder. Yesterday I spent many hours behind one from our local place. I had 11 HUGE pine trees around our carport.
https://www.aulro.com/afvb/attachmen...a-p1190173.jpg
I had them felled in two stages, then cut up all the pine, made many huge bonfires with the branches ... and have a stack of useless pine for burning stacked along the shed.
now pine is soft.
YouTube
https://youtu.be/z-IOXzQh5sE
I hired this sucker from the local hire place. 32hp engine joystick control... it worked HARD ... and still took me a whole day to do all of the stump. Don't even dream of hiring a "manual" one where you have to pivot the thing yourself. They have only one of these ( a quality Red Roo unit) ... and several of the big tracked b@stards. They reckon everyone hires the smaller one once ..... and never again. It was $398 for a days hire, and I got 16 stumps around the yard out. The pine stumps were at least the size of yours. The biggest took me an hour. They are quite a bit larger at ground level than they are at the cut. So think 1.5metres in your case. I cut down as far the the stump grinder would dig.
You will be left with a lot of ground up dirt/ground wood left over. I just levelled it all around the area with the blade on the back of the tractor.
seeya,
Shane L.