First download odin3 v3.09,stock
samsung galaxy grand prime.md5,samsung mobile usb driver installer,usb cable=unzip odin3.zip on your desktop,then run samsung mobile usb driver setup,when setup finishes,open the odin3 folder on your desk top,find the odin3 icon then left click on it and a menu will pop up find on the list run as administrator...and click that option as well as yes on the next pop up that says proceed as administrator,now odin3 3.09 the samsung mobile device flashing program should be open,now ready the device by pressing key combo-volume down+power+home till green android appears woth option volume down:restart-volume up:comtinue.of course contonue...
Now you should see a screen that say's: Do not remove from usb.
Now the phone is ready.
Now back to odin3 on the pc,look at the first box located at the top left corner of you screen and see if you notice if it says connected,if yes then your device is connected,now locate button PDA and click on it,and it will take you to you documents,now locate the samsung galaxy grand prime.md5.zip in you pc and select it;find start button at the bottem right of screen and click on it and you should now see a green bar filling up on the pc,and a blue bar on the device,when both bars are filled you get a notice of success and your device will reboot itself;if by chance the bar goes red and says fail,disconnect the usb and remove the battery you can then reinsert the battery and try again,and addition you can attempt this process as many times you like it will not put the computer at any risks at all...