6-Run the script, in the File dialog choose the zip file generate by SweetHome 3D EXPORT to HTML5 XML/OBJ plugin
It's possible use the imported model with blender render and blender engine (the script add Logic blocks for FPS game like behavior)
To render with blender cycles it's necessary import the materials. Try use https://wiki.blender.org/index.php/Extensions:2.6/Py/Scripts/Material/Blender_Cycles_Materials_Converter
The Sweethome 3D XML/OBJ file has ligth power information, the HTML5 format don't.
Version 1.3.1 and above of the HTML export plugin no longer exports the object of the house structure and no more work with blender script.