A simple upper cover lifter with little holes to avoid foreign parts to enter in the printer (es. bugs) .
For the order of assembly, macth the number on the part with the one on the assembly STEP or image.
I suggest to do a little test with the fits before to do all the print.
You can print it with any tipe of support, no screws for assembly needed.
I print that with grass green pla from Sunlu.
This is tested on P1S but probably work fine also on X1. If someone try it on a X1 let me know.