You can dnload UE's instructions of building either a 6 or 8 spyder ultralight diff. They have plenty of pics and are explained well enough to understand what you're trying to accomplish.

The only thing no one ever mentions is george16's trick with marker/dye to dbl check mesh. You kinda need to know what you're looking for to use that, but it provides a visual on locating pinion on the ring and quality of the mesh.

If you've ever done a 1:1 diff you'll know what I mean.