I’m creating a game and it haves only my own characters so far. As Paragon characters are avaiable on the store for free.I just wanted to modify the meshes and use it in my game, but it seems that I can’t for the meshes are not editable in the editor. So is it can be used only without any modification? Will you release the source file for the assets?
In editor you have only limited possibilities to edit meshes, generally you can’t. You can change/edit material, hide some bones, modify animations - in limited way.
I don’t think source will be published, but you can import character fbx to most of 3d software and edit it - if you have skills. You are asking, so you have no skills, so better talk with someone who is skilled modeler or animator.
you will need to modify the meshes in an outside program such as blender, maya, or max. to do this you will need to export the skeletal mesh to a format such as fbx, then import it into the modeling software then make your changes.