Open the battery door and remove the battery. Dry the battery with a tissue or a towel. (Don't put it back in yet.) Shake as much water out of your Tamagotchi as you can. (Be careful to not accidently drop or throw your Tamagotchi while doing this.) Dry the battery compartment with a tissue, being careful to not bend the battery contacts or leave bits of tissue stuck in it. Find someplace dry you can leave your Tamagotchi for a few days. Set your Tamagotchi on its side there, leaning up against something, with the battery compartment facing out. Be patient. After a few days, put the battery back in, then press the Reset button on the back. You should see the Download / Reset menu appear on the screen. Select Download. Your Tamagotchi character(s) should reappear. Don't forget to set your Tamagotchi's clock to the right date and time.