Removing Chocolate Stain from Wool Christening Shawl?

I have a beautiful, fine christening shawl hand knitted in a lacy pattern in 2 ply wool some 40 years ago by my mother. Unfortuntely somehow it was stored away without anyone noticing the chocolate. It looks as it if it may have been liquid dark chocolate. We have our first grandchild due shortly and we would love to be able to use it. What would be the best way to try and remove the chocolate? Any advice would be much appreciated.

By Brenda W from Staffordshire, UK