Hello -- I am changing my thermostat (97 Ram 2500 V-10) and have wrestled with alternator and housing and have them removed. I finally removed the t-stat as it was pretty well stuck in there. I am trying to remove the o-ring down inside the block (rubber seal was visibly corroded) in order to replace it but it won't come out. Short of banging and prying, I am not sure what to do. I don't want to damage anything so I was hoping for some pearls of wisdom in my attempt to get it out. Does it pry up and out (rather difficult)? What am I missing? Thanks!

James