The first thing we did was put together the parts that did have instructions. The flying buttresses, rose window, and roof arches. These went together easily. There are some chunky flash areas and some other bits that need to be trimmed up a bit but a big exacto is the only tool I used in the basic assembly.
It's actually a bit tricky to put all the parts together and I strongly suggest you dry fit everything before you use any glue. Make sure everything is snug and take your time putting the thing together. The walls fit together via a tab and slot system which is really quite ingenious and there is some play in the whole structure which makes it easier to assemble. The tabs that show on the outside can be filled with the decorative elements that come with the kit or filled with putty or something. The only loose parts I had at this point were the flying buttresses. I'm going to be gluing mine together on the final assembly.
Anyway that's basic assemble of this kit. I'm really happy with it so far. I think I have fewer than three hours on the assemble and I was bumbling around a bit. I would say that this kit could go together in less than an hour if someone was really in a rush or they had some experiences with the other kits like it. I'll follow this up with final assembly and painting. With any luck I'll have a new building for my table by the end of the week!