[Q] adb editing problem on editing build.prop topic

hello there can anyone help me coz am trying to edit the lcd display intensity coz i messed with it i changed the value to 790 now am stack the tablet does not navigate apps and icons are too big. now i used adb and this is what i get every time
[I][I][COLOR="Lime"]Microsoft Windows [Version 6.4.9841]
(c) 2014 Microsoft Corporation. All rights reserved.

C:\Program Files\Minimal ADB and Fastboot>adb devices
List of devices attached
0123456789ABCDEF device


C:\Program Files\Minimal ADB and Fastboot>adb shell
shell@android:/ $ su
su
root@android:/ # mount -o remount ,rw/system/build.prop
mount -o remount ,rw/system/build.prop
Usage: mount [-r] [-w] [-o options] [-t type] device directory
1|root@android:/ # adb pull /system/build.prop
adb pull /system/build.prop
error: device not found
1|root@android:/ #

anyone who can help coz i want to edit the build.prop so that my device gets back to normal