I have a Savage Model 30 (a.k.a. Stevens Model 77 or Springfield Model 67) 12 Ga. pump shotgun that has some dirt and rust issues. I have disassembled the shotgun to clean, however I need to take apart the operating handle. I have an exploded diagram of the handle showing the parts but can't determine exactly how to remove the front/rear operating bar collars. There are no apparent screws, spring clips, etc. I would be grateful if anyone can give me some direction on breakdown. Thanks!