HOW TO UPDATE FROM KITKAT OR LOLLIPOP TO MARSHMALLOW ON YOUR HTC DESIRE 820 DUAL (820U).

Hi, friends...
                   Now time comes to upgrade your phone to Marshmallow 6.0, So we have a                   Marshmallow Ruu, we don't have to go through the Ota update method, So quickly match       your phones specifications to following and get prepared to upgrade :-

     NOTICE :- THIS TUTORIAL IS ONLY FOR INDIAN VERSION, Read it carefully and proceed through same as described hence I am not responsible for any damage or brick of your phone.PLEASE MATCH THE FOLLOWING...
                        MODEL CODE            :- A51 DTUL (820U) Dual Sim.
                        CID NO                        :- HTC_38.

      OK, If your phone matches above configuration than consider following two methods as         your phone is stock position or rooted.

              First Method :- This method is for stock rom phones, who have locked bootloader                   with stock recovery but update problem or no software update tab in setting of                         phone. ( Locked bootloader & Non-rooted )
             
               1) Charge your phone upto 80% minimum.
               2) Backups your contacts, apps+data,sms,bookmarks with any backup app.Move                         your important data from internal storage to sdcard.
               3) Download This Marshmallow Ruu.
               4) Rename it to 0PFJIMG.zip, Note:- first alphabet is number zero (0) not O for                               orange.
               5) Place the file in root path of external sdcard.
               6) Power off your phone, after 10 second press volume down button along with                             power button to boot into bootloader.
               7) In bootloader, the file automatically detected and start flashing.Now don't mess                       with phone, it will take half hour to fully flashed.
                   
                      Enjoy the Marshmallow!!

                 Second Method :- This method for unlocked bootloader, modified and rooted                            phones, So first we have to relock bootloader before update.

                   1) Charge your phone upto 80% minimum.
                   2) Backups your contacts, apps+data,sms,bookmarks with any backup app.Move                         your important data from internal storage to sdcard.
                   3) Relock bootloader with this easy software, or you can use fastboot method.
                   4) Download This Marshmallow Ruu.

                   5) Rename it to 0PFJIMG.zip, Note:- first alphabet is number zero (0) not O for                               orange.

                   6) Place the file in root path of external sdcard.

                   7) Power off your phone, after 10 second press volume down button along with                             power button to boot into bootloader.

                   8) In bootloader, the file automatically detected and start flashing.Now don't                                 mess with phone, it will take half hour to fully flashed.

                   

                      Enjoy the Marshmallow!!