El Capitan Remove Finder from Application Switcher (cmd tab)
The file is protected by System Integrity Protection as outlined here.

By disabling SIP you will be able to edit the info.plist again.

So boot to Recovery Mode by pressing cmdR while booting.


Open Terminal.app (menubar -> Utilites -> Terminal)
Enter csrutil disable
Reboot your Mac 
Edit the file /System/Library/CoreServices/Finder.app/Contents/Info.plist
Reboot again to Recovery Mode and enable SIP again: csrutil enable
Reboot your Mac




You should also be able to edit the file directly after booting to Recovery Mode without disabling SIP:

/Volumes/name_of_main_volume/usr/bin/nano /Volumes/name_of_main_volume/System/Library/CoreServices/Finder.app/Contents/Info.plist




You may have codesign Finder.app afterwards:

sudo codesign -fs - /System/Library/CoreServices/Finder.app/