Download CM 10.2 Nightly ROM from here.
CyanogenMod Downloads
- grab the latest CM 10.2 build.
- do not unzip the contents and save the file on your PC.
Download Gapps for Android 4.3 custom ROMs from here.
Download GApps for Android
- don’t unzip the archive.
Use the USB cable and connect the SGS4 with your PC.
Move both zip files to your phone’s internal storage. When the files are copied, disconnect the device from PC.
Power off the phone.
Boot your device into CWM / TWRP Recovery now.
- if you don’t know how to do it, then you might find this guide here helpful.
How to enter Samsung Galaxy S4 Recovery Mode
First thing that you have to do is to create a full NANDROID backup for the ROM that is currently installed on your device:
- CWM Recovery: select ‘backup and restore’, then use the Backup option to complete the process.
- TWRP Revovery: press Backup. Select the system parts you want to save, then confirm.
Next, apply the ‘factory reset’:
- CWM Recovery: select ‘wipe data/ factory reset’ and confirm this process.
- TWRP Recovery: press Wipe, then Factory Reset. Confirm.
- when the factory reset is complete, continue with the tutorial.
Now you can flash the new custom ROM files:
- for CWM Recovery: select ‘install zip from sdcard’, then ‘choose zip from sdcard’ and find the CM 10.2 Nightly zip file. Install it.
- for TWRP Recovery press Install, then you should browse your device’s internal SDcard for the CM 10.2 zip. Confirm the process by sliding the blue button.
> the installation process shouldn’t take more than a couple of minutes to complete.
When all files have been installed with success, return to the main recovery screen.
Select ‘reboot system now’ for the CWM Recovery or Restart/ Reboot option for the TWRP Recovery.
The first boot process of this new ROM shouldn’t take more than a couple of minutes to update. That is why you should wait until the home screen appears without pressing any buttons.
Enter the Google Account details when the home screen appears, so that you’ll take control over the AT&T Galaxy S4 and the CM 10.2 Nightly custom ROM