I just took mine apart. The top part that some people are having problems with can be loosened with a pair of needle nose pliers. Mine happen to have a 45 degree bend at the nose which made it doublely easier to take apart. My pump was just getting pretty groady on the outside and I was thinking maybe crap was getting inside of it.

I guess there's no pdf on how all the parts come together? Good thing I took some pics of this thing while I was taking it apart.

Oh yeah, this pump has been one of the best things I ever bought for my bike. Love this thing (road morph). I don't think there's another frame pump that can pump a tire up to 120 pounds, is there? Also from my experience the gauge is not bad, but I don't even use it. Just pump it up to as far as I can.