SystemUI temporary replacement without soft-brick risk

Hello,

I would like to replace systemui.apk on my telephone. I have a Samsung SM-G920W8 device.

How do I know which systemui.apk files on these forums are compatible with my device ?

Is it possible to replace systemui.apk without soft-bricking my device? My device isn't compatible with Cyanogenmod and the current firmware ( 5.1.1 ) is not available on the internet for disaster recovery.

Here is what I tried to get systemui.apk installed without the risk of soft-brick.

1. adb shell


2. su


3. mount -o tmpfs null /system/priv-app/SystemUI


4. I dropped a new SystemUI.apk into the folder ( the old SystemUI.apk and arm64/SystemUI.odex files can no longer be seen from shell )


5. I rm -rf /data/dalvikcache


6. kill ( process ids of zygote and zygote-64 ).

I thought this would force a software reboot of the device and would cause the new apk to be loaded. Unfortunately, the old systemui is still being loaded.

The reason I am trying it this way, is that a tmpfs is wipe at reboot, so if I 'soft-brick' my device, I can just hard-reboot it.

What am I missing to make this work?

Thanks,

Me