I feel, just the steps rendered obsolete by this in text form.
I agree that the old 3DS method is no longer the only option. I also agree it is 'obsolete' in terms of 3ds max being a very old and unsupported program thats not easily installed, the process itself to make a mod is still a tried and true method though, as its how the original papy devs made the game essentially. It will give you the full range of capabilities to make a mod.
With that said though, the Blender plugin competes against it very well and does give a great alternative. I just recently completed from scratch a completely new mod (ICR mod level of quality/features) using only the blender plugin method. However before you get too excited, the blender plugin is still in alpha phase and there are still some unsupported features, which unless you are very experienced in mod creation will not be able complete a mod without doing some manual cleanup of the PAS file it exports so its not fully 'user friendly' quite yet. The main things are car damage and driver animations, the plugin does not support animation frames and for mod damage the way blender translates meshes of the same vertex count messes up the export of the papy blender plugin so manual cleaning of the PAS exported is constantly needed, I made a script to auto clean it for me.
If you really want the technical details, trials and tribulations of user feedback (and to give your own), and my own testing you can follow the official thread here:
https://www.adrd-forums.net/index/threads/blender-add-on-papynr.1411/page-3#post-4920
So in short, while I would like to eventually make a tutorial on the new method, its not ready yet and any documentation I'd make would need further and constant updates as TShirt is still developing the plugin so some things that may not be working now might be easier to do later. With hopeful animation support this will allow us to fully make NR2003 content 100% free from 3DS Max 8 plugin method.
If you are just beginning though you can still use the plugin to easily make a mod that has no car damage or animation for the exterior driver. By the time you learn how to import the car bodies and wheels into NR2003 the damage issue may be fixed and animation support may be support a few months from now.