I need to do ours soon so I asked a few mates. Apparently it's much easier with the side panels and the tailgate off and the carpet out. If you can get one a spot weld remover is a good idea so that you can neatly drill out the original spot welds and replace them with a plug of MIG when you refit the new panel.
I'm told it's a day's job if all goes to plan.
Best of luck.