Though, the CyanogenMod 12 will give you taste about Android 5.0 Lollipop on your Galaxy Grand Duos (GT-I9082/ I9082L), please note that this is not a fully functional ROM, which means it is not ready to be used as a daily driver yet. A number of things do not work, so use them at your own risk.

What does works (as of November 27): Wi-Fi Bluetooth RIL (Calls, SMS, Mobile Data) Dual SIM Sensors (Accelerometer, Compass, Light, Proximity, etc.) Camera (photo) Video playback Audio (playback & recording) GPS What does not work (As of November 27) Screen record FM Radio Wi-Fi HAL (i.e. Scanning MAC Address Randomization) Sim Tool Kit (STK) not fully working Video in YouTube app sometimes freeze Camera app sometimes crash on close Unable to un-pin screen without rebooting 2G/3G toggle does not work properly in non-English language Swipe typing and face unlock SIM with PIN may not work properly Important: Back up any important data before installing the ROM

Installation Instruction :

Note: Before installing this ROM, download [HERE] and install the CWM recovery with SELinux support. Older CWM recovery will result in a “status 7” error. Does not work on 4.1 stock ROM’s bootloader, please upgrade to 4.2 before flashing.

  1. Download the CWM 12 ROM zip file [HERE] [HERE] and copy the zip file to root of your SD card (not in any folder)
  2. Now, boot your Grand Duos into custom recovery mode. To do so, switch Off  your device and press Volume (+), Menu, Power buttons together.
  3. From recovery, do a full wipe (cache partition, data wipe/factory reset, dalvic cache)
  4. Now, choose install ZIP from SD card and select the “cm-12-20141116-UNOFFICIAL-i9082.zip” (use Vol buttons for navigation) and flash it.
  5. If you want, flash Google Apps [Download here] and Superuser too.
  6. Once again, do a full wipe (Data wipe/ Factory reset, cache partition and dalvic cache)
  7. Now, go to the main menu and select ‘reboot system now’. That is it. Your Samsung Galaxy Grand Duos will boot into Android 5.0 Lollipop OS version. Important Note: Keep in mind that, currently above mentioned ROM is experimental and contain several bugs. It may brick your device, so use at your own risk! (Source – XDA)