Radio theft code. I refuse to pay someone to give me a theftlock code for my new 2000 Chevy

Question

I refuse to pay someone to give me a theftlock code for my new 2000 Chevy Trailblazer that I just picked up from an auction. Unhook battery to do some engine work and the dealership wants $30. Is there anyone out there that can throw me a bone please.Thanks Jason

I have a 2004 Chevy Impala with a Delco Radio, IT doesn't show RDS on the face of the radio. Ive tried pushing 2/3 and 1/4 together at the same time, and nothing comes up with a 3 ditg number. Is there anything else I can do to retreive these numbers that are needed?