I hope they look good when you figure it out. You’ve been focused for sure.
Look at the top of the truck. It looks like they screw on. You may need to do a little dissection. My set comes in tomorrow. I may know more after I get it. FWIW, I like the detail of the trucks. The 3rd rail skirts look good on my E5s, but look bulky on a streamliner. My opinion, not gospel.