LAVA ANDROID

Press Vol Up + Left soft key and power buttons
+ Press home key (center soft key).
Press vol down to go to Wipe data/factory reset option.
Press volume down to go to "Yes-delete all user data" option.
Reboot device after done.

or

Press And Hold Volume Up + Power Key

Use Volume Keys To Go Up and Down

Select wipe data/Factory reset

Press power key to select

Now Select Reboot System Now