New Progress Transfer Case on '98 Dodge Ram Locked in 2H. How to shift?

has anyone worked on a new progress transfer case so they can tell me if ther eis a way to ‘unstick’ one. Mine is stuck and it was that way when i purchased the vehicle and I am not sure what happened. A guy that works on these told me to pull the welch plug on the front side of the transfer case. He told me there should be a spring and plug on the other side that will come out. And he told me if that does not work then pull the vacuum switch on top of the transfer case and see if the two things will allow it to shift.
So I slid under the truck and no welch plug where he told me there was one, maybe he meant on the back side of the transfer case??? Anyone know.
he also told me what might have happened is that someone shifted it hard enough to pass two keepers that come out and block the unit from shifting. Again anyone know?
Anyone know if there is a way to service this case other than the way I have described?