Any ideas?

I use acetone or goop off, mainly acetone.  You can get these at Lowe's, Home Depot, Wally World, etc.  I use acetone to clean my aluminun shafts before fletching also.

Thanks, I will give it a try.....

Acetone is pretty strong stuff.  It will soften and could damage the finish on a wood-riser bow.  I use denatured alcohol and apply it with a sponge or rag to the leather grip to saturate it.  Will take a few minutes for the leather to become thoroughly soaked.  That softens the glue undereneath, if it's a contact cement like barge cement, and you can then pull off the grip and clean up any additional contact cement with alcohol on a rag.  Even alcohol can soften the finish some so try not to get it anywhere but on and under the grip.  

Some folks use other adhesives that are just about impossible to remove.  On those, the leather might have to be ripped off, and you may need to sand the residue and refinish the grip area of the bow.  Good luck.