Just use the numbered buttons on your stereo to enter the code once you've powered the stereo up. Do you have a number in your code that you don't have on the stereo itself?...
Press button marked (1) three times to get the three
Press button marked (2) eight times to get the eight
Press button marked (3) three times to get the three
Press button marked (4) five times to get the five
Really sorry but I think I gave you the wrong procedure...
If what I told you before does not work then the following will be correct!
Switch on the radio and code should be displayed...
Press button (1) once
Press the tuning/seek button repeatedly until the first number of your code (3) is displayed
Press button (1) once to store the first number
Press the tuning/seek button repeatedly until the second number of your code (8) is displayed
Press button (1) once to store the second number
Press the tuning/seek button repeatedly until the third number of your code (3) is displayed
Press button (1) once to store the third number
Press the tuning/seek button repeatedly until the fourth number of your code (5) is displayed
Press button (1) once to store the fourth number