For the head gaskets, the two dowel pins should keep things in alignment. They are still available from Ford, base part number is "6A008".
For intake gasket, scrape old gasket material, wipe down with acetone. THIN bead of blue RTV on both head, intake. Allow to "skin" over, then assemble.
For exhaust gasket, again, make sure both mating surfaces are scraped and clean. THIN bead of red RTV, if you can get it in there. Install front/rear bolts first, two turns each. Let the gasket/manifold hang on these two bolts while you install the rest. Some gasket are slotted on the front/rear bolts to allow you to drop it in once those two bolts are threaded in.
Not too difficult. Take it slow, ask questions, and get a repair manual. Don't forget to adjust the valves when you're done.
'00 CNG Crown Vic daily driver