[HIDDEN FEATURE]
Supported Devices:
[LUMIA ONLY]
730,735,830,930,950/950XL.
NOTE: Lumia 830 doesn't have a LED. The windows button will blink as a notification LED. Lumia 930 LED Notification may not work!
[PROCEDURE]
Step 1: Extract the above downloaded i386.rar file in your PC.
Step 2: Move the downloaded CAB* file (i386-extracted) into a folder named CABs in C: (C:\CABs\microsoft.ms_weh_ledalert.mainos.cbs_360f71f2e2672 7f4e3adf7edb819581c2bb14e7c.cab)
Step 3: Open CMD with administrative rights and navigate to the iutool folder (i386-extracted).
Step 4: Now type it--> iutool -V -p C:\CABs
Step 5: WAIT! If failed, RETRY!**
[Notices]
*CAB file is only for builds 14393.693 or later. For older build CAB files, head on to Microsoft Update Catalog above.
**The IUTOOL will forcibly try to install the update CAB file. If it shows error, please keep on retrying it until the phone restarts and successfully installs the update.
Youtube
Successfully tested on Lumia 730!