Use the search function in your file manager. It's probably somewhere like android/data
I couldn't find it anywhere using windows explorer. searched for the full folder name and just spotify.......nothing.
So I followed the process anyway but it didn't work.
I don't think windows can normally access the system files on an android. Get a file manager from google play and use that.
IT CAN BE DONE! Worked for me (Samsung S4), check: