I have MTH passenger set 20-6530. This is a set of 5 modern ribbed side 70 foot PRR passenger cars with lighted interiors. To change a lamp it is necessary to remove 10 screws just to access the light bar that holds the lamps. Eight screws attach the underframe to the body. Two more screws attach the floor to the underframe. Then 6 more screws to remove the light bar to access the lamps.