unblocking passwords

hey, i need to unblock a password that my parents had set so that my younger brother wouldn’t download his games and bog-down our computer….again. 😛 but when i asked them they thought it would be a good idea if they didn’t disguss it with anyone but themselves. this plan just doesn’t work for me. its not like i am trying to rob a bank, i just want my iTunes back on my computer.. if you could PLEASE help a teenage girl that needs her music that would be awesome!!!!! get back to me ASAP please!