Tree clearing technique?

I've got a couple of pasture hillsides that have been left to grow up to cedar trees (eastern red cedar) for decades. They're dense enough that nothing grows underneath and the hillside is fairly steep.
The only tool I have is a D6c with an open brush guard.
They push out easy but the problem is having enough room to move and get the downed trees out of the way.

Erosion is a consideration....thought I might cut some lanes through the cedars this fall, seed them down and then do some more clearing next summer after I got some grass established.

A while back I ran across an army manual on clearing techniques in dense growth but I've lost track of it.
I'm considering buying a rake for this and other small tree clearing but haven't pulled the trigger on that yet.
An excavator would probably be a better tool but I have to use what I have.

Any advice on how to go about it?

Thanks

Tree clearing technique?