Hello! I've come here with a somewhat manual way to recover avatars
Im assuming you already have unity and the version required but if not please visit the vrchat download page to get the version of unity or you can use their creator companion!
For starters you need to get the avatar ripped!
Please use below the method below if you don't know how to rip said avatar
Tutorial (How To Find a VRCA)
For examples i will be using something i ripped as a base to show what to do!
Before continuing i will not be covering toggles the rip will provide the animation for it to be implemented but their are very many videos on to make toggles an you can repair what was broken!
I will also not provide links for shaders and such in here as everything i will use will be public shaders only for the purpose of this!
1st thing is making the project
I recommend using these within your project

2nd Step Before you import your model please delete these 2 folders so it doesn't throw a fit with the VRC SDK
Delete the things i have highlighted when opening the folder!



This keeps the folder organized aswell as removes all not needed things!
3rd thing i would do is drag this folder within UNITY's Asset Section!
it should show up like so

4th thing is putting the model in the scene!
Now that the model is now inside there are a few thing i would do from this point forward
There will be errors but first you need to clear the avatars scripts that includes these 3

Make sure to right click and click remove component

There will be a lot of scripts inside of the avatar but don't worry they aren't hard to find most of them are typically used for phys bones or world props on a avatar
Here is a simple way to find them
on the top left there is hierarchy search bar inside the search bar search for "script"
In my project it would look something like this

When clicked on in the inspector it will show the Script that needs to be replaced. 9 times out of 10 its physbones
Click add to component if you are sure its physbones

When putting the physbones on the model you might notice something called "Root Transform" in the Inspector make sure to drag the body part for example im using "butt_L" and im rooting that script to that part of the body

There are videos on Physbones and more in depth this is gonna be a long post and im not trying to sit here for hours typing this!
Next thing is i would do is fixing your materials!
Alot of people use different shaders (Ex. Poiyomi Liltoon Arktoon Ect.) i will be using vrchat unlit shader and also showing you where the shaders for the original model are stored. please note they dont work!. when ripping shaders it can only pull the properties logic but not the sub logic of a shader so IT WONT WORK!
1st is fixing the materials
In this package im using as reference i've highlighted all my materials

At the top of the inspector should show the shader

Swap it to the desired shader or the original shader if you have it
all the original shaders that are on this model are located here!

Ok so i pretty much summed up what i would do to repair an avatar the last thing i would go for is repairing toggles but like i stated in the start there many videos out there that show to to create toggles, its just up to you to implement it on the avatar
Last thing is adding the avatar descriptor
Click your avatar in the hierarchy and look at the inspector

It should be empty
Now add the avatar descriptor

Log into the control panel after fixing the view point to in between the eyes
Something like this

Theres is so much more to explain but its hard to explain in words! good luck ripping and hopefully this help some of yall!