i just did it this last weekend (factory hitch on an '04) its really easy. the bumper facia already has guides on it, where to cut and where to drill. the only thing that takes a little bit of time and patience is taking the bumper facia off, the rest of it is a slam dunk. nothing beats the fit and finish of the factory system, soo worth the extra bucks.
'04 4.0L 4x4 / 4" Hybrid lift, Bilstein 5150's (sans jks9602's), 255/70-16 BFG AT's, SD40, jks disco's, fipk, skids, hooks, kevin's sliders & an ECTED