Fuel injectors--follow up questions

Thanks to those that responded to my "fuel injector prep" thread. Now here is the follow up.

1990 is the XJ in question...

I am going to try to swap these with a little dismantling as possible. I have unbolted the fuel rail already. I don't see a real need to disconnect the pressure regulator or the line at the rear of the guel rail. I should get enough "give" from the fuel line without doing that.

Now, have y'all had better success seating the new injectors in the fuel rail and then setting it into the engine as one big piece, or seat the injectors in the engine, and slip the fuel rail over top of the 6 new injectors?

Just trying to eliminate trial and error the best I can.

I put them in the manifold and then put on the rail. Also, I never pull the pressure regulator.