There is no rwp file for this repaint.
The actual name for this repaint is "
NJ Transit Bombardier Comet Cab Cars"
It helps when you specify exact information in your posts.
The file to download from the library is a zip file, not a rwp.
Open the zip file, and read the readme.docx. It is rather terse:
Paste the last 2 folders here
C:\Program Files (x86)\Steam\SteamApps\common\RailWorks\Assets\RSC\P32Pack01\RailVehicles\Passengers\Shoreliner
Copy the Geo file from the DrivingTrailer\Engine folder to the NJT\Engine Folders
For sounds paste them into the Shoreliner audio folder and edit the Proxyxml and write the names of the sound files where they belong.
It is very strange that a Workshop item requires a 3rd-party add-on that is not available on Steam.
This is not supposed to be permitted.
Also, this isn't mention anywhere, I could only see this requirement by editing the scenario in RW-Tools.
Where did you see that "it says to download it from here"?