Hey fellas. I hope this hasn't been asked too many times before.

What's the fastest way to kill a big 80ft pine tree that's 3 to 4ft thick at the base?

I used a gallon of gly so far and it killed the green but its starting to come back green.
I chopped a few chunks out of the trunk and soaked it in 40% gly every week for a month.
Ran out of gly, dug holes around trunk, filled with used motor oil then covered back up and started with another gallon of gly because I don't want motor oil in the dirt. Its in the edge of my vegetable garden or I'd just poison it with used motor oil.

Its leaning towards the neighbors house and will land in his backyard and on his roof. The previous neighbor wanted it cut down on my dime. There were 15 trees in a row. Half of them gonna hit houses. I cut all of them except this one because we ran out of time and needed a boom lift. Now I'm having to wait to cut it in winter when my garden is out the way. So I wanted to kill it because its filling my gutters up, making a mess and blocking sun.

I know if I kill it, its a lot harder to remove. It being brittle and dead, snapping off falling opposite direction. Anyways, I want it dead. I will cross that bridge when I get there.

I'm gonna have $100 invested in gly just trying to kill the damn thing. I should have drilled holes in it and filled them with gly or salt or something but I dont want it to look bad Incase it dies and lands on Tupac's house nextdoor.