The best way is to use desiccant. Most hardware stores sell the stuff that can be "recharged" in the oven. You'll want to use a larger container to place the desiccant in the bottom. Place the smaller container inside containing the fungus. Then put the lid on the larger container and wait a couple days. Don't put fresh harvested fungus in the device as this will overload the desiccant. Let them dry for 10-12 hours first. If you want to supercharge this device, you can fit it with a small fan to move air around and exchange moisture between the fungus and desiccant. This will double the drying speed.NEVER allow the fungus and desiccant to come into contact as the desiccant is pretty toxic.

Anything over about 50C will slowly degrade the actives. At about 100C, you'll notice a substantial loss. Making tea has minimal degradation only because of the brief time at these high temperatures.