In my honest opinion, you should start another one. Making a bow faster when it is already finished is too little too late.
If you insist on increasing this bow's performance, your options are very limited due to the glue that was used for the backing. Any attempt to steam, heat or boil the bow into shape will result in delamination. The only viable option is to kerf bend the tips into recurves. Recurving or reflexing will increase early draw weight, and over-all draw weight, and at least improve performance.
Shortening the bow (the only other option that does not require heat) is out of the question, since the bow is already short with 64".