Browse Addon files in blender

space_userpref_changes.py

## EDIT space_userpref.py
# e.g. on windows, C:\Program Files\Blender Foundation\Blender 2.93\2.93\scripts\startup\bl_ui\space_userpref.py
# on windows, edit as admin

# CLOSE BLENDER AND BACKUP THAT FILE BEFORE STARTING!!

## before "class USERPREF_PT_addons(...)"
class USER_OT_AddonBrowse(bpy.types.Operator):
    bl_idname = "user.browse_addon"
    bl_label = "Browse Files"
    
    path: bpy.props.StringProperty()
    
    def execute(self, context):
        from webbrowser import open
        open(self.path)
        return {'FINISHED'}

## after "sub.operator("preferences.addon_remove")", with the same number of tabs as there
sub.operator("user.browse_addon", icon='FILEBROWSER').path = os.path.dirname(mod.__file__)

# inside "classes = (...)"  near the end of the file
USER_OT_AddonBrowse,