Yeah, make sure you download it on your PC, because Android somehow doesn't recognize ".apk-" and just displays it as (a corrupted) ".apk". If you rename it and then view it through some kind of explorer, you want to see the red Jelly Bean icon and not a blank page (that means it's corrupted).
I agree with Tom. After you rename it, it will receive the stock 'red jelly bean UI' icon. When that happens, you are ready to go. DON'T FORGET TO ADD '.BAK' AT THE STOCK 'SYSTEMUI.APK' and 'SYSTEMUI.OBEX' END. Paste it into /system ( preferably with TWRP ), if you didn't do it with TWRP, then don't forget about the lines in terminal emulator :
mount -o remount,rw / system
and continue by pasting it into /system.
Enjoy... (or cry). xD
It may work, it may not work. It's experimental, until a solution is found.
Also, I think disabling acer.shell increases the chances to get it to work.
Edited by execpwd, 06 November 2013 - 08:29 PM.