There is not a video on the internet explaining how to assemble a dayan? I looked on youtube but can't find one. I just got done lubing..
Assemble the innermost core like it's a 2x2 core.
It's easier if you make one full hemisphere by placing some pieces next to the part of the white core that has the three screws in it. The big piece that everything rotates around.
Attach your black shield pieces. Screw these in as tight as they go. If they're loose they'll wiggle causing the center pieces to lock up one another.
From there add four center pieces, then the edges and corners in that layer. I usually start with white and work my way up the cube. Once the bottom layer is there put in your orbital centers. So if you did white on bottom you'd then do blue, red, green, and orange.
Once you have the first layer and the four orbital centers complete then add in your dedges. Just put them in by pressing them in place or slide the pieces in from the top.
Now that you have three layers done do the centers of the U layer.
Finally, add dedges and corners alternatively like you would if you were putting together a 3x3.
Sometimes as you add centers you'll notice it's sticking out in an awkward angle. That's because the piece isn't sitting correctly in place. To fix this just put your thumb on the back of the piece and your index finger under the corner opposite the stalk of the center and push down with your thumb while pulling up with your index finger. It will pop into place and then your centers will sit nice and flat. Sorry there's no video that I know of. I plan on making one eventually but I'm still waiting to get a camera. If you need help look at lancetheblueknight's tutorial on how to assemble a Rubik's 4x4. They're very similar the only difference is the center pieces.