We have a Coleman Lantern and want to replace its battery but cannot get the old one out.?

It is a large battery and looks as though you can just pull it out but we yanked and yanked and it is in there solid. We called Coleman and they said it is in there with foam and some kind of glue but it should be able to be pulled out. We don't want to break the thing by yanking too hard. Anyone ever take a battery out of a lantern and if so, how did you get it out if it was stuck. Thanks.