can a longbow draw weight be reduced

Yes

But more importantly What bow is it? Make, # at draw, and what is your goal # at draw when finished?  

a bow can be reduced and it can also be ruened.

Yes. If you are serious about reducing the weight, give Jim Belcher of Belcher bows a call. He'll do it in a professional manner and make sure it is done correctly.

The longer the bow usually the more weight you can lose depending on how wide the limbs are to start with.On shorter bows or bows with narrow limbs you will be more limited on what you can do.If you have never done it or built bows I suggest having someone like Belcher do it or tell you what can be done.jmo