Hey adventurer, so the process for this piece goes as such… There are slots in the post for the signs to slide into and they may fit a little tight, but nothing to fight with. The post slots on the bottom for Winterhold and Rorikstead actually have a slight angle to them so just keep that in mind when you push the signs in those slots. As for the rest of the signs on the front flat surface of the post I just used a dab of super glue to attach them on. Also, Whiterun has a small thinner piece for the backside of it and it just needs glued on. I thought making that one double sided was needed to look better as you will see that sign from both sides.
*Make sure for the sign post part that you have auto tree supports on. Should be saved in the print profile for it but I am still learning the ropes on here with uploading files.