How to Install Android 4.4.2 KitKat based Smasher X 5.1 ROM on Sprint Galaxy Note 2 SPH-L900

1. Connect your device to PC using USB cable and then copy downloaded files to the SD card of your device. Important: Don’t extract any files.
2. Disconnect USB and then turn off your Sprint Galaxy Note 2 SPH-L900.
3. Now, boot into recovery mode. To do so, press and hold Volume Up, Home and Power button together until Samsung logo flash twice and then leave the button. You should see recovery menu soon. In recovery use Volume Keys to navigate between option and Power button to select an option. Alternatively try this: Recovery Mode without Key Combination.
4. Perform a Nandroid backup of your existing ROM that you can restore later if this new ROM not work or you want to go back into your previous ROM. To perform a backup, select Backup and Restore, then on the next screen, select Backup again. Go back to main recovery menu after backup is complete.
5. Now, perform data wiping task. To do so, select wipe data/factory reset, then select Yes on next screen to confirm your action. Wait few minutes till the data wipe is complete. Now come back to CWM recovery main menu. Select wipe cache partition and after wiping process done, select Wipe Dalvik Cache under advance option to perform Dalvik cache wiping.
6. Select install zip from sdcard, then select choose zip from sdcard (or /sdcard1 for external storage). Now, locate the Smasher X 5.1 Zip file that you copied earlier in Step 1 and select it by pressing Power button. Confirm installation by selecting Yes – Install _____.zip on the next screen. The ROM installation will begin.
7. Once the ROM installation process end, repeat the step 6 but choose the gapps-kk-20140105-signed.zip file instead of ROM zip to install the Google apps package.
8. When installation is completed, go back to the main recovery menu and select reboot system now to reboot your Sprint Galaxy Note 2 SPH-L900 and boot up into Android 4.4.2 KitKat ROM Smasher X 5.1. 
9. Returning to Previous ROM: To go back to your previous ROM, boot into recovery, select backup and restore then restore your previous ROM by selecting it from the list.

Tutorial For TWRP Recovery Users:

1. Connect your device to PC using USB cable and then copy downloaded files to the SD card of your device. Important: Don’t extract any files.
2. Disconnect USB and then turn off your Sprint Galaxy Note 2 SPH-L900.
3. Now, boot into recovery mode. To do so, press and hold Volume Up, Home and Power button together until Samsung logo flash twice and then leave the button. You should see recovery menu soon. In recovery use Volume Keys to navigate between option and Power button to select an option. Alternatively try this: Recovery Mode without Key Combination.
4. Create a Backup using TWRP Backup Option.
5. Perform a Factory Reset (this will delete all apps and their settings and game progress). To do this, Tap on Wipe, then at the bottom of the screen do a Swipe on the ‘Swipe to factory reset‘ option.
6. Now its time to add zip file for flashing. Tap on Install, then browse to the location where you saved the files and tap on the Smasher X 5.1 Zip file. Then tap on Add More Zips, and add gapps-kk-20140105-signed.zip. Now at the bottom of the screen, do a swipe on the Swipe to confirm flash option to begin flashing.
7. When installation is completed, go back to the main recovery menu and tap on Reboot and then, tap on System to reboot your Sprint Galaxy Note 2 SPH-L900 and boot up into Android 4.4.2 KitKat ROM Smasher X 5.1.
8. Returning to Previous ROM: To go back to your previous ROM, boot into recovery, select Backup then through Restore option, restore your previous ROM by selecting it from the list.

Congrats! Android 4.4.2 KitKat firmware based custom ROM Smasher X 5.1 is now installed and running on your Sprint Galaxy Note 2 SPH-L900. If you stuck on Smasher X boot logo more than 5 minutes then go back to recovery and perform Step 5 (wiping task) few more times before rebooting your device.