Your _p.psarc is just the file extension of the custom dlc's (songs) you will download from here if you are using Rocksmith on a PC. Your dlc folder is where you will place all of your custom dlc's and is found in your Rocksmith2014 directory Usually C:/Program Files/Steam/SteamApps/common/Rocksmith2014 or where ever you installed Rocksmith. Video guide: How to use CDLC (PC) http://customsforge.com/topic/938-video-guide-how-to-use-cdlc-pc/?do=findComment&comment=4007