1 - Open the project zomboid directory

You can paste this on the address bar to go directly to it:
%userprofile%\Zomboid\Workshop

2 - copy the directory InternetRadioTEMPLATE

3 - paste the InternetRadioTEMPLATE

4 - rename the directory and files to avoid conflict:

Example: 
from:
%userprofile%\Zomboid\Workshop\InternetRadioTEMPLATE\Contents\mods\InternetRadioTEMPLATE\42.0\media\lua\client\InternetRadioTEMPLATE.lua
%userprofile%\Zomboid\Workshop\InternetRadioTEMPLATE\Contents\mods\InternetRadioTEMPLATE
%userprofile%\Zomboid\Workshop\InternetRadioTEMPLATE

to:
%userprofile%\Zomboid\Workshop\InternetRadioCLNW\Contents\mods\InternetRadioCLNW\42.0\media\lua\client\InternetRadioCLNW.lua
%userprofile%\Zomboid\Workshop\InternetRadioCLNW\Contents\mods\InternetRadioCLNW
%userprofile%\Zomboid\Workshop\InternetRadioCLNW

5 - Edit the radio frequency, name and url on the lua file:
%userprofile%\Zomboid\Workshop\InternetRadioCLNW\Contents\mods\InternetRadioCLNW\42.0\media\lua\client\InternetRadioCLNW.lua

6 - Edit the project zomboid mod info
%userprofile%\Zomboid\Workshop\InternetRadioCLNW\Contents\mods\InternetRadioCLNW\42.0\mod.info

7 - Overwrite image files

8 - Open the game

9 - Test the mod

10 - Go back to main menu

11 - Workshop upload