Just give them some room, feed them lots and keep them warm. Mine pupate in slightly higher than room temp with minimal problems as long as I keep the humidity around 60%. However, they do pupate faster between 29-30C. They eat like you cannot believe, though- so keep the food coming. One larva can eat 25-500mg of food a day! They like it pretty humid, too: 50-70%. I feed compost material: bananas, melon rinds, peppers, etc. They prefer wet, softish food (but not wet food; they get stuck in it and die). Mine prefer fruits and soft veggies to grain products, but this "wet" food in a warm wet environment is gonna get moldy if you feed too much! I just let mine pupate in the larvae bin and I get about a 70-80% eclosure rate, but there are more elaborate set ups that will increase success too closer to 100%. I just don't care enough to build the ramps etc required lol Depending on how much and what you are feeding, your temps and humidity it can take several weeks for the lavae to pupate and several more for them to eclose. As long as they are eating and moving, you're doing fine! When they are ready to pupate they turn dark, though, so don't think those ones are dead! If they are kinda hard and black they are mature or pupating larvae; if they are kinda squished looking and soft and black they are dead.