Not sure why you don't follow the suggestion of renting a stump
grinder.* That's what they were made for.

* Because they're outrageously expensive here for what they do
and that much isn't in the budget for this project .


I'm curious, what was the cost for you to rent one for 4 hours?



Examples below are not from the OP area but from my area
in S. Ontario Canada in cheapo Canadian dollars :

Stump Grinder, Walk Behind Self Propelled 26 HP
$235.00 per day

Manufacturer: Toro
Model: STX26
Length (in): 78
Width (in): 34
Height (in): 46
Weight (lbs): 1,200
Engine Brand: Kawasaki
HP: 26
Fuel Type: Gas
Blade Size (in): 19
Cutting Depth (in): 12.5
Notes: Trailer For $20 Extra



Stump Grinder, Walk Behind Self Propelled 38 HP
$275.00 per day

Manufacturer: Toro
Model: STX-38
Weight (lbs.): 1,750
Engine Brand: Kohler
HP: 38
Fuel Type: Gas
Blade Size (in.): 22.25
Cutting Depth (in.): 18
Manufacturer: Toro
Model:: STX38
Length (in.): 95
Width (in.): 34
Height (in.): 51

http://www.coleman-equipment.com/rental-rates/results/

John T.