Metalman01

Best answer as chosen by Asker / Ratings
First you need to beat all bosses, including Baal. Once this is done start a new game on the difficulty beaten then transmute a town portal tome and Wirts leg. This opens the red portal in the rogue camp. It's also worth remembering if you have been in a game where the cow level was open and someone killed the cow king, you can't open the cow level anymore in that difficulty level.