How to remove file from /system/xbin Android

Question

I had copy tcpdump to /system/xbin on my device.

How can I remove It? when I try :

adb shell rm /system/xbin

I get:

rm failed for /system/xbin/tcpdump, Read-only file system

Answer 1

I had to do

adb root

adb remount

then rm is possible

Answer 2

There are two ways:

adb root
adb remount
adb shell rm /system/xbin/tcpdump

or

adb shell
su
mount -o remount,rw /system
adb shell rm /system/xbin/tcpdump