Change the system APK to the android Simulator

Modified an Android app, such as launcher. then, a launcher.apk is compiled separately. How can I put this apk in the simulator to view the effect without building the entire image? The methods found on the Internet are directly adb install. However, after I try it, the system will prompt that the apk already exists and cannot be put in. Is my method wrong or is it simply not available on the Internet? Ask colleagues to know that they are doing this:

Start the simulator first:

 

> Emulator-avd myavd

 

Then remount:

 

>Adb remount
Remount succeeded

 

Enter adb shell:

 

>Adb shell
#Rm/system/app/Launcher.apk
Rm/system/app/Launcher.apk

Press Ctrl + c to exit shell
#^ C

 

Import New apk:

>Adb push C:/Launcher.apk/system/app

 

Restart the simulator or do not restart the simulator. Turn off the original AP and you will be able to see the modified effect.