If your pads were glued-in, they were not meant to be replaced, you'll need to get creative with some other pads or material.
Many helmets, especially the higher end ones, have pads held in place with hook-and-loop fastening for just the occasion where you need or want to swap them out. Our store stocks a limited selection of replacement pads for just such an occasion. Thing is, once a helmet style changes, helmet companies will rarely produce replacement pads for the long term, so you're left trying to source NOS pads somewhere else, or the suggestion from the helmet company or bike shop to replace the whole helmet...