How to Edit Init.rc in Android

hi
i want to change the GPS serial port in Mini210S android system image to be


# Define the GPS device
    setprop ro.kernel.android.gps s3c2410_serial0

how i can do this?? 
i try doing this after android is start but i cant

Use ADB to PULL the file down to you computer, edit it there and then use
ADB to PUSH the file back to the Mini210s. 

You then need to reboot the device for change to take effect.

I recently did this to make similar changes and it works.

Dave...

PS.. Your issue may be that serial0 defaults to being the debug interface
so you may need to change this first to get the init.rc file changes to
work.

thanks it is work