Most likely you can. Get an exacto knife and try to pry around on it gently. If its aleenes tacky glue, water might soften the glue too.

I would do what wacky suggested. You might soak the entire piece in water and see if the glue turns white (reverts) and if it does, then it should all come apart. I have had success popping off tesserae by using an old paring knife. I insert the blade as far as possible under the tess and then rock it back and forth sideways.

I've tried this technique and it seems to be working. Not super easy but not super hard to get the soaked tess off. I think it will be worth it. Thanks!