You could probably take off the leaves that look totally lost already, but I'd leave most of them on. If your tree suffered a shock, it will need a little bit of phtosynthesis to recuperate. Normally total defoliation is not recommended for a weak tree.
When it has finished making use of a leaf, it will drop the leaf. I'd let it run its course. But, when a leaf is totally brown/black, don't leave it on or else it will make a home for mealy bugs.
I HATE MEALY BUGS
pootsie