The passenger cars are easy to open. There are four screws in the corners of the cars. These cars do not have the double-sided tape that the first run of Union Pacific Excursion cars had. The absence of tape makes opening these cars easy. Remember the wire to the roof LED lights is usually at the vestibule door end of the cars.
The "Manhattan Island" observation is the most difficult to open because the rear coupler must be removed to access the long bolt that goes through the observation floor and into a raised nut fitting in the roof of the car. It takes several tries to get the long bolt to enter the roof nut thread when putting the car back together. Not impossible, just hit or miss because the nut fitting is raised from the underside of the interior roof, and the bolt does not just drop in.
Remember to have a container to put the loose screws in while the car is apart. Searching the floor for missing screws is not fun. Do NOT over-tighten the screws because the posts that they go into are soft plastic and can strip out if too much pressure is used in tightening them.
Have fun detailing these cars. The passengers help add visual depth to the interior of the cars.
If you haven't watched Mr. Muffins layout videos, pop some popcorn this holiday vacation and enjoy the Muffin's amazing layout.
Season's Greetings and Merry Christmas, John Rowlen