Model, texture and shader handling for mods

Hi
I am developing a RPG core system as an asset for unity, the question is, lets say i have a sword that has a component called weapon and this component is inherited from Item class, now, if i want to give others the ability to add mods to this core system in future, for example, their own sword to the item data base, how should i handle models and textures and shaders so that the mod making guy can export it and put it in a folder and the game re-read it and add it to the item data base? I had seen it done in KSP, not sure how they handle it though. What i would like to have is a wizard in Unity that the mod developer would use to add the models etc, and then export sort of package (Asset file or what ever proper) and the users can put it in a folder on the game end and the system would read everything back and add the new sword (with model and all the stuff) back to the data base.
what is the proper way of approaching this?

What you are searching for are AssetBundles. Here’s the link to the Unity Manual on AssetBundles. Package your mods into AssetBundles and then, at runtime, check a certain folder (your choice) and subfolders thereof for AssetBundles and load them with the WWW class. Searching folders and subfolders for AssetBundles may be done with the C# Directory class (MSDN link).