Here's how I set the door.
You might will need a helper inside the trailer. I used the egress window to get into the trailer. Some older Trilliums don't have an egress window.
I used duct tape to position the door. Note: The raised area on the belly band will not align with the raised band on the door. It's a flaw in the mold. I eyeballed the gaps on the sides. I filled 11 of the 12 holes leaving the upper rear. I attached the upper hinge by the one screw and adjusted things do the hinge pin was parallel to the gap and centered. I then marked and drilled the remaining 5 holes. A countersink center punch is useful here. Once drilled you can attach the upper hinge. The helper needs to align the plate and attach the nuts.
I positioned the lower hinge and measured between upper and lower rear holes. I made a spacing tool using a piece of scrape wood and a couple of nails. With this I laid out the lower hinge. Drill, attach, done. Don't forget to let the helper out of the trailer.