See
http://www.televue.com/engine/TV3b_p...1#.U87kW-OSy5I and click on Nagler Type 4 Eyepiece Instructions.
The upper part of the eyepiece pulls up and can be quite disconcerting if the friction is a little light as can be the case. The eyepiece is heavy and sometimes the weight pulls the bottom of the eyepiece down as you hold the upper section.
If you have one that is tight then that's good. I think the friction has to be factory changed. Even if a little loose it is fine and you'll get used to it. Just don't let go! I usually leave it all the way down and place my eye at the appropriate position. I don't use the pupil guide either.
In a Newtonian the 22NT4 is a very nice eyepiece but does benefit from a Paracorr to clean up the very outer edge as there is ever so slight curvature.
