@torqued
The official instructions are somewhere in Foxipaws's discord IIRC but I don't feel like digging.
So after you get the main avatar package loaded, you drag and drop the Dalmatian unitypackage into Assets and import it, same as other packages.
It'll add a folder called Oreo Dalmatian Honey Bear. Open that, then open the folder called Materials.
There'll be 3 materials: Body, Hair 3, and Neckfluff. You just drag those into the material slots on the avatar (or a duplicate of the avatar).