How do you install aftermarket pipes on a Shadow VT750C?

I'd like to switch my factory pipes on a 2006 Shadow Aero VT750C for a set of Vance & Hines shortshots. It would appear that the factory pipes are welded on. Do I need to unbolt the upper part of the pipes from the engine and replace the whole thing, or somehow undo the welds from where the lower (single) pipe joins where the upper pipes run up into the engine? Thanks!