Flash files are used for do software or update mobile old firmware. During flashing it can take little bit time. If you expert in flashing you can flash different mobile without flashing box. like flash with flashing tool phoenix or nemesis service. It is little bit difficult for you with flashing these tools. However it is same thing first of all you will need to download latest flash files of your mobile first. During using some times your mobile working so slow or completely break with the reason of its flash files.
Before flashing you will need to take backup of your important data like images,messages and contacts. After flashing you will lose your all of data and your mobiles will restored in its original settings. You can download latest flash from provided links