The easiest fix would be to download your ROM of choice and then transfer that zip file to the SD card you use in your phone. You might need an adapter to plug the card into your computer but you can grab one almost anywhere (WalMart, Walgreen's,etc) for ~$5.
Once you have your ROM on the SD card, pop the card back in your phone and install the ROM through TWRP.
Posted via the Android Central App