My, my, my, what a huge stag! IF you want to keep the plant as-is, you'll need some strong people to help you re-mount it. You actually won't "mount" it, since it is just too bulky/too thick to do so. You'll have to re-hang it instead. You would have to use a cable or large chain to do this. I have never had a situation such as this, so what follows is all pretty much guess-work. This is what I would do though.
Get some sort of heavy stake or pipe, long enough to penetrate this "ball" of ferns from top to bottom, and having it long enough to have some extra. Drive this stake/pipe completely through the fern-ball, from top to bottom. Attach your cable/chain to the top portion of the stake/pipe, grasp the bottom end of the stake/pipe (you might be able to do this with strong hands/body but you may have to use a large vice-gripe or a similar tool) and pull that stake/pipe with cable/chain attached, through the fern-ball. Attach something to the cable/chain that would support a bit of the bottom of the fern-ball. This ball is mostly thick, tough, fibrous material, so you won't need much support. You just don't want the cable/chain to pull back through the fern-ball when you hoist it back up. Attach a hook or similar to the top end of the cable/chain and then attach that to a block-and-tackle/pulley which would be attached to a really large, strong tree limb or similar. This fern-ball might weigh several hundred pounds. Now you can hoist that staghorn back up.
Alternately, divide the sucker into more manageable "pieces", and mount the divisions however you wish.
Ken
