I would do as Coyote Machine suggests in post #49. Accept, after cutting or breaking as much roots as possible, I wouldn't cut the trees until after trying to push them over. That way you can push higher up on the trunk of the tree with the bucket and use the leverage and weight of the hole tree to help uproot and topple them.
A word of caution on pushing trees over.
I have a brand new (in 2012) Kubota
M7040, Deluxe cab, FEL, my first new tractor, my baby.
I pushed over several pine trees about 20' high using the FEL and my very heavy blower on the 3 pt. Very proud of myself and my tractor
Then I pushed one over and had a hard time backing up.
The stump and root ball came up under my tractor as I pushed. It snagged the guard for the fuel tank which had an angle arm bracket as the leading edge of the guard.
The angle arm was ripped off the aluminum under-pan for the fuel tank.
6 years later I still see the bend angle piece under my tractor and leave it as a visible reminder.
Now, I use a ladder and get as high up in the tree as I can and attached a very strong nylon tow strap for larger trucks.
I use the strap as it is much easier to lift than my 50 ton rated chain.
Now I assemble enough chain so that I am far back from the tree and cannot be hit as it comes down.
If needed, I can move around the tree leaving the strap in place and dragging the chains.
This is why I am a strong advocate for the puller with the additional hydraulic cylinder. Someday I hope to buy one.
Dave
M7040