A good place for authoritative and helpful information about these invasives and their management can be found at this link.

Here is a link that might be useful: TNC Invasives site

make a path...and then keep it clear.

"save" a tree that's infested with vines. and then keep it clear.

clear a spot surrounding the tree...and keep it clear.

then pick a new tree, and save that tree and keep the ground nearby clear.

Eventually all your little cleared spots will connect and you'll suddenly realize you have entire areas that are restored

The only way to make progress is to attack it in stages, and then keep on top of the areas that you've already worked on.

good luck. it can be done. it will take time. just don't let the unaddressed sections of the land get you depressed...you'll get to it all (eventually)