Hard reset BLU 5.3 2 D551a

Very important DO NOT press power button and DO NOT unplug the charger cable.

With your phone off press Volume up and plug the charger , hold until you see this menu:
Use Volume up  to select RECOVERY MODE and Volume down to enter.

If you did right you will be in this screen:

Press home button (little house) on the bottom of the screen and you will be redirect to this page:

With volume button choose WIPE DATA/FACTORY RESET and to select press the menu button :

Select yes  and press menu button again.

Once is finished choose REBOOT SYSTEM NOW and press menu button.