How do I change radio stations on my Kenwood car stereo. It was in the vehicle when purchased, but no instruction manual

SOURCE: Blaupunkt 300 car radio & cassette

I need a better model number so that I can help you. "Car 300" didn't find anything do you see a model number or name?

SOURCE: Manual for a car radio

Your best bet would be to look on JVC.com I bought a JVC head unit from a friend, and i printed out a manual on the jvc website, and it was free

SOURCE: manually change radio stations?

Here is how to manually tune your radio.
1 Press the SOURCE button until a radio
frequency appears in the display.
2 Press the BAND button repeatedly until the
desired radio band is displayed.
Each press changes the band:
→ F1(FM1) → F2(FM2) → AM
3 Press the TUNE button repeatedly until "DX
SEEK" and "SEEK" disappear from the display.
NOTE
The initial mode is DX SEEK.
4 Press the g DN or f UP button to move
downward or upward one step respectively until
the desired station frequency is displayed.
NOTE
The ST indicator or STEREO indicator appears on the
display when a Stereo FM station is tuned in


You can also look at your manual here for any other ? you might have
http://akamaipix.crutchfield.com/Manuals/500/500CDM7874.PDF

SOURCE: car stereo displays 000ZAA

000ZAA:
remove front panel and press reset button with ballpen

SOURCE: My Kenwood KDC-241 car stereo loses it memory when

you need to rewire it,it seem like you connect the YELLOW (memory wire)to the ignition line.
You will need to connect it to constant pwr line and the RED to the IGNITION line