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If you mean just the command "su", it's placed in "/system/bin"
If you refer to "Superuser" application, this should be "Superuser.apk" in "/system/app"
Anyway, it's hard to remove it from phone (and I don't recommend it) without root permissions, but you can try to do it from computer with Adnroid SDK, maybe it will work (if you have older SDK version, skip to commands, adb is placed in "tools" folder in older versions, in "platform-tools" in the new SDK version):
- download the SDK from
Android SDK | Android Developers
- uppack it, run setup and download the tools
- now tun these commands from right tools folder (see upper) from commandline (without quoted comments):
adb remount /*remount phone*/
adb shell /*run shell from phone*/
su /*logon as superuser, probably you still have root access and this will work*/
rm /system/app/Superuser.apk /*delete Superuser application*/
rm /system/bin/su /*delete su command, but if you just want to delete the icon from Launcher, it's maybe better to skip this*/
exit /*exit from superuser mode*/
exit /*exit from shell*/
