Remove the 4 nuts holding the rail.. wiggle each injector and lift up on rail. A trick to remove if it'* never been done is to spray a little silicone at each lower o ring (where the injector sits in the manifold). There won't be enough silicone to hurt anything..don't use the whole can.
Yes, two rings per injector, being careful on the bottom ring. Those wafers you see are hard and brittle. I use a little vasoline to lube then rings after installation to assist them in going back into the fuel rail..and then the manifold.
00 Regal GS: All kinds of cool stuff.