2000 Cavalier transmittier

i have a 2000 cavalier LS when i bought it the owners gave me a transmitter the only problem was that, the unlock buttom did not work so i ordered a new one. the problem is i don't know how to program it and i checked with the gm dealer they want 65 dollar to reprogram it i think thats a rip off because i know it only takes about 30 seconds to do this. please anyone help me out please i'm starting to rip out hairs over this car:banghead: