The general direction is going to need some work, but on top of that there's a couple of additional things which will need addressing - the speed, and the frame jumps.
First thing I'm looking at is the speed. By the looks of it they've used the common tactic of recording it at a slower pace then speeding it up in post production
Here I changed the speed by 50%, but to match the speed of the FotL video I'd be inclined to go at 25%.
Big problem which is instantly noticeable in my demo - the miming needs to be spot on to work. Mine is far from it; this is because it's extremely difficult to 'play' a song at a different tempo than what you're used to.
Although I don't know who I'm going to be borrowing for the recreation (or who'll be playing what), as soon as we're sorted we'll need to actually practice the song a lot, as opposed to doing what I did and just thinking "what the hell" and getting on with it.
On that note - Sir, do you know where one could find tabs for the song? I tried looking the other day and didn't have much luck, and my interpretation skills aren't all that.