removing resin from an artifact

Hi guys, I have a problem. I tryed to conserve one artefact in a small glass container. I poured epoxy resin in three layers but I couldn’t stop bubbles. Worst thing is that resin is yellowish. So I wonder if I can remove resin from a, like small cup, glass without breaking glass container as it is engraved. Or not, just to extract artefact from resin and then try again with another epoxy. My guess is that component B was exposed too much to oxygen. Thank you for reply!