Hi Judy,
I don’t have many good options here. Resin is a wonderful glue, so this isn’t going to be easy.
I have used methylene chloride to get resin out of metal bezels. The resin loosens up away from the edges of the bezel and pops out in one piece. It might work for your situation. If you try this, please know that this chemical can be EXTREMELY dangerous to your health. Follow all proper safety precautions when using. You should be able to find it at a home improvement store.
Your second choice would be to use some type of sanding/cutting tool to either sand off the metal pieces or somehow cut underneath them (cutting between the numbers and the wood). This method is either going to be tedious or almost impossible. Depending on how the letters got put onto the wood, there may not be much of a layer of resin between them and the wood. Once again, please take proper safety precautions. You don’t want to breathe any resin dust.