A tree the size you have there can still be brought back to an upright
position.
The supplyies I suggest for you is get some old hose and some cable and
turnbuckles and some long stakes.
Make sure you get the stakes in deep and then loop the cable around the
tree and connect it to the turnbuckle then connect the turnbuckle to
cable from the stake.
This will give an easy way to tighten your cable up you can do it in a
rather small space.
Peiodically tighten the cable until it the tree is in the position you
desire.
Keep it staked for at least a year after that to make sure itis fully
rooted.
Chuckie