The reason ADB is reporting no devices are found may be because (1) your device is bricked, which probably means you are not going to be able to pull/push files from/to your device, (2) you do not have ADB drivers for your device properly installed on your PC, and/or (3) you do not have
USB debugging enabled in your tablet's
Developer options settings.
It's good you are learning how to use ADB and there are plenty of ADB tutorials to be found via Google, etc.; e.g.,
HERE.
Here is what you specifically ask for.
Pulling the build.prop file from your tablet to your PC is easy, just use these commands.
Code:
adb wait-for-device
adb pull /system/build.prop
adb kill-server
Pushing the build.prop file from your PC to your tablet is more complicated.
(1) Your tablet must have root access. If it doesn't, attempts at pushing the file to your tablet's /system directory will fail.
(2) Along with having root access, you must have SuperSU or Superuser, and Busybox installed on the tablet.
(3) You have to temporarily set your tablet's /system directory's properties from RO to RW, which must be done quickly because your tablet's OS monitors the /system directory's properties and will reboot the tablet if it detects the directory's properties have been changed from RO.
(4) To issue the ADB commands as quickly as possible, the commands must be put into a DOS batch command script file. For example, create and run a batch file named doit.bat containing the following commands.
Code:
adb wait-for-device
adb push build.prop /build.prop
adb shell "su -c 'stop ric'"
adb shell "su -c 'busybox pkill -f /sbin/ric'"
adb shell "su -c 'mount -ro remount,rw /'"
adb shell "su -c 'chmod 0440 /sbin/ric'"
adb shell "su -c 'stop ric'"
adb shell "su -c 'busybox pkill -f /sbin/ric'"
adb shell "su -c 'mount -ro remount,rw /system'"
adb shell "su -c 'busybox cp -af /build.prop /system/build.prop'"
adb shell "su -c 'chmod 0744 /system/build.prop'"
adb shell "su -c 'rm /build.prop'"
adb shell "exit"
adb kill-server
Good luck.
