Contact one of the guys that does restorations. They should be able to help.
Sometimes, by heating a bolt of the same size and thread, and screwing it into the insert, you may release the adhesive. Beware, if does not come easily, you may cause the wood to splinter around the insert when you pull it out. Some inserts have teeth on the outside to hold it in place, to prevent the insert from turning after it is installed.