It's ok I found it myself
1) turn the phone off
2) push and hold in order vol up and down and power bottom simultaneously while powering up the unit Screen will show up as Boot Mode Selection Menu.
3) press Volume down key to cycle through choices until you get "Android Recovery"
4) then press Volume up key to boot in this mode "recovery mode"
5) you'll a pic of the "triangle with an exclamation mark (!) / Android" lay back , Make sure you push on the vol up and down again together, and A Recovery Menu will come up
6) you use the vol down to scroll highlighting wipe data factory reset or wipe cache partition, based on your option then you tap on the power key to select.
"Warring in case you're going to select wipe data factory reset, make sure you backup your phone first using gmail or SD card, there'll be no way possible for you to get those datas back, if they were not saved somewhere before the action was taken".
7) you'll get the yes or no confirmation, you select "yes" to do it or you hit "no" in case you changed your mind.
8) after wards It will take you back to the same recovery mode menu, then you hit the first option which is "Reboot System now" tapping on the power key. and your phone will come on it may take you up to 3,4 or 5 minutes to boot up.