Old 1984 Ranger. Still nice. Pedestal/Butt seat handle broken. Can't stick it back in. The seat is a normal adjustable seat post with an extension tube. Probably pressed on. Not a pin type post. The old flat bottom post. I have another adjustable post and want to use it to replace the "gas" cylinder post part of butt post. Want to take off the extension tube and put it on the new post. Old post says "Do Not Open". Wish I could cut and hammer and twist and all that. What is the danger? Why do they say Do Not Open. How do I proceed. Is there a spring that will fly or gas or explosion or what?