How to remove the SIM Toolkit from my phone? (Without root or flashing any ROM)
Connect Your Phone to PC Using Data Cable.
Turn on USB Debugging
Setup ADB Connection
Type 

adb shell

Hit Enter and type again this

pm uninstall -k --user 0 com.android.stk


or    

pm uninstall -k --user 0 com.android.stk2



Application Remove Example Image