first of all you need MAIN, FS and Custpack to flash your phone, MAIN should end with mbn, Fs should end with fbn, you need MAIn to able to generate the simlock patch. flashing is like formating or upgrading like NOKIA phone, patching is for unlocking your phone, generate vkp with simlock generate using your MAIN and apply the patching guide. first download xs from here and post the log so that we can give you the firmware for you phone