There are some methods to convert the models with bones. The first one is to use unity studio and in the export option select the bone/skin. The problem is that the fbx exported sometimes is not correctly viewed in 3d software like 3ds max or others. So just try to see if you are lucky. The second method consist to extract the assets with disunity and convert the files extracted (the models should be in .43 format) and open them using Noesis + unity import plugin. For more info just take a look ath Xentax forum, where you can find the tools you need.
PS: I can't remember what is the last Unity studio release, but i suggest you to check for the last one on github.
EDIT: I just noticed that Hallow created a very useful tutorial that uses a similar method: https://www.vg-resource.com/thread-31141.html
For now forget to obtain animation in a frendly user way. You need specific knowledges about the format and hex.
PS: I can't remember what is the last Unity studio release, but i suggest you to check for the last one on github.
EDIT: I just noticed that Hallow created a very useful tutorial that uses a similar method: https://www.vg-resource.com/thread-31141.html
For now forget to obtain animation in a frendly user way. You need specific knowledges about the format and hex.