How to master reset the LG optimus Black with the Hardware keys

Re: How to master reset the LG optimus Black with the Hardwa

hey i have a lg e420 phone and i don't remember my patten then my 4n is locked how to factory reset my 4n
 
Volume down. Turn off cell. Hold power and volume down even after LG logo appears. It will then shoe you then little Android. Release buttons. Scroll down using volume key to hard reset. Select it by pushing power button. Now kick back and let the little Android do the rest. Bam! Your cell is done. Hope that helps man..