This type of operation delete all installed apps on phone, and also delete all files in the internal SD card, so before proceed copy all your data to PC or to external SD card. If you have a CWN/TWRP recovery, do a full backup from recovery to external SD card.

To use this tool, you need the 2 file EBR1 and EBR2 from your current ROM. You can get them from ROM update file in FlashTool format (check here on NeedROM if exist), or from a backup

EBR v01.00  Download
EBR v03.00  Download