Oh boy... I installed the lighting kits for 8 of my Walthers Amtrak Superliners. And it was a pain in the arse to install. The shell was difficult to remove, and once I finally got that off, when I installed the light, the tabs on the lighting kit are cheaply made, and when I installed the shell back on, the light strip grounded out on the roof of the metal shell, and fried the lights. Not once, but twice it happened before I got smart and put a peice of black tape under the roof.
Now I also have the Walthers Streamliners and those lighting kits are much, much better and a lot easier to not only remove the roof shell, but the lights have a better tab design than the Superliner light kits.
I'm not sure if your Amfleet are similar to the Superliners, but if they are, all I can say is good luck, and remember to put a piece of electrical tape under the roof!