How do I restore the reverse camera guide lines

I would recommend consulting the owners manual to learn the various controls and settings that will remove and restore the grid. Not having the vehicle in front of me - I cannot guess at what buttons need to be pressed. Try this for the manual -- if you do not have one: https://assets.sia.toyota.com/publications/en/om-s/OM48A09U/pdf/OM48A09U.pdf