In order to force reset a Oneplus device, you must first power off the device. Then you must hold down the Power and Volume Down buttons simultaneously until you see the Oneplus logo onscreen. Once that appears, release both buttons and wait for the options menu to appear. Here, select “Wipe Data/Factory Reset” using either the volume keys or Power button and then confirm your selection with another press of the Power button. Your phone will now begin its factory reset process before rebooting itself into its normal operating mode.