K frame barrel removal?

[trotterlg]

I have a very well used K frame that has had the barrel cut just in front of the ejector rod clip thing on the bottom of the barrel.  It is in 32-20.  I just picked up a used nice looking 5 inch barrel for it.  I have changed out and built lots of rifle barrels, this will be the first time I have changed out a revolver barrel.  Which way does the little pin drive out?  How tight will the barrel be in the frame and what is the proper way to hold the frame? How much gap should there be between the cylinder and the barrel when I put it back on?  What else will surprise me when I do the swap?  Larry

[S.B.]

You're better off and it will be cheaper to take it to a knowledgable gunsmith? As for cylinder gap, depends on the type of bullets you'll be using in it?
I bought a model 27 at one time that the frame was cracked (read useless)because of an armature gunsmith attempt to remove the barrel? Expensive deal to get it replaced by S&W?