plug in a mouse
go to the upper-right corner and swipe down to show the status bar
click the gear icon (settings)
in the list click "Backup & reset"
click "Factory data reset"
click "Reset mbx"
click "Erase everything"
an erasing screen will appear
then it will partially boot-up
then it will reboot once
then it'll be factory reset
all your data (slides, text, data) is not removed because that is stored on the oalla server. This only resets the hardware firmware.