As Anthony said, you'll want to cut each branch back to the first pair of leaves and let it grow..... It'll push out 2 new shoots from the base of each remaining leaf, once you've got about 6-8 leaves, you can repeat the process. This will give you a bifurcating branch structure (each branch divides into 2) and you'll also get some new buds popping in other places too.
The only thing I'd do differently than Anthony is, I'd fertilize it much stronger...
And if you don't already know...do not over water it! In needs much less water than any other tree I know of. In order to make the roots grow, it needs to completely dry out between waterings.
I let mine dry until the leaves begin to show tiny lines (begin shriveling) then I hit it.