Reprogram Keyless Entry 2003 Sunfire

I've lost one of my Fobs and plan to buy another from Ebay. My dealer wants a mint to reprogram the new Fob. Does anyone know the procedure to reprogram?

2003 Sunfire 4 - door model.

Thanks

This is done by using your vin #. your dealer is the only people that can do this. most dealers will not do it if you bought a keyfob from elsewhere. get the fob from them and they will do it.