Easiest way... Not cheap (USD 595.00) but perfect...
MP3, IPOD, CD or XM (satellite) inputs included! Just add an IPod as I do... Looks original but offers today’s technology; fits dash without any modifications; 4 × 45 watts RMS output allows up to 180 watts of audio power; green AM/FM dial scale looks like original; AM or FM band selected with slide-bar like original; analog controls look like the original radio. 7/16” shafts for mounting exactly match original radio; LED dial lights; digitally tuned.
Sorry, just noticed that you own a 69 Bird. Nevertheless, just take a look at the above mentioned web link, there´s an option for 1969 Chevelle/Camaro/Nova AM/FM/Stereo Radio for $595.00, too. Being a 68 guy I´m not sure if this radio will fit your 69 car...