Swap Guide

I know there is alot of information out there about 3.8 to LT1 swaps but i cant find an actuall guide on how would be the best way to swap the engines step by step i know all the parts that need swapped and how to swap them but i was just wondering where i should start and where to go from there, also on my z28 its a dual cat exhaust and off the drivers side exhaust manifold there is a what seems to be medium sized metal barrel looking thing and i have headers and a new y pipe that will eliminate that i was also wondering if that part was needed

a barrel shaped thing??? is it a flex pipe? i would imagine you can do without it, just have the exhaust clamped togehter properly, or welded.