A bit of setup required if you want to use the Juice and Ripstik model on your own avatar. All I ask is that you don't redistribute or resell the models of the juice and skateboard as they are my own original assets. Feel free to redistribute using your own avatars and assets!
Setup for Custom Avatars:
Initial setup
For experienced creators only! Please have at least a general understanding of unity and avatar creation for VRC.
Must be in an AV3 Project with final IK installed.
Requires a shader that supports packed textures for the Juice and Skateboard https://github.com/RetroGEO/reroStandard/releases/tag/1.0.8
or
https://github.com/MochiesCode/Mochies-Unity-Shaders/releases
Poiyomis pro version of his shader was used for the refraction on the Ocean Sprays plastic.
https://www.patreon.com/poiyomi/posts
The previous two shaders will work fine with just transparency (Mochies does support refraction now!)
You can skip on the shaders if you don't plan on using either of the models.

The hierarchy must match the example avatars armature (at least for the hips and legs) in order for the animations to function. Ex. Hips -> L_Leg -> L_Knee -> L_Ankle
Make a duplicate of your leg bones in blender with the added "_main" in their name like the example avatar. They will need to be set as your avatars' legs in unity through the rig configuration menu. They will serve as your actual IK'd limbs in vrchat so your legs can properly transition between normal walking and standing on the skateboard.


In unity copy over all game objects from the example aside from the armature, body mesh, and "Dummy Hips".
Next, Reassign all the constraint targets (aside from the RipStik and OceanSpray constraints) to all the corresponding bones on your armature.
Now create a new GameObject on your Hip bone, duplicate your leg bones, then place them under the new object. This will serve as your new "Dummy Hips" object and should replicate the component values, naming conventions, and placement in your avatars hierarchy.
Your hierarchy should look something like this.
IMPORTANT NOTE:
Make sure you add the same menu and parameters from the example avatars descriptor along with the locomotion and FX layers! Nothing will work without all of them added to your descriptor!

Apologies for the tedious setup. I'll get an automated script made If I post similar stuff in the future.
If lots of people are having issues I'll make a setup vid!