Listen up, on S4, you only have to press VOLUME UP button and POWER BUTTON at the same time. And keep holding it until the actual recover options appear on your phone screen. Do not let go when you see that little message show up on upper left screen. Keep holding it until you actually see the recovery options before you on your screen. DO NOT HOLD THE HOME BUTTON WHATSOEVER!!! Now, if you see that your phone is going into another restart without options appearing, just hold the VOLUME UP button and hold it until you see the recovery
http://esausilva.com/2010/10/02/how-to-set-up-adb-android-debug-bridge-in-mac-osx/
How to upgrade on encrypted devices
http://en.eladalfassa.com/2013/05/upgrading-cyanogenmod-on-an-encrypted-device/
http://developer.android.com/sdk/index.html
./adb sideload ~/cm-10.2.1-jfltecan.zip
http://www.androidcentral.com/how-manually-update-your-nexus-tablet-kitkat
Replace step 6 and 7 with the following:
# mount -t tmpfs none /data
# mkdir media
$ adb push cm-10.1-20130430-NIGHTLY-i9100.zip /data/media/update.zip