To use this devil fruit, the user has to touch the object they want to put a simulacrum into- not very complicated. Which personality they duplicate is the challenging part, as it can go two ways. First the user can not specify the personality they wish to copy, and have a random personality (usually the strongest personality nearest to the user) become a simulacrum. Or the user can predetermine a personality that they wish to use, by tapping the person with the desired personality and saying 'Copy' then tapping the desired object and saying 'Render Data'. The user can also 'Save' a 'Copy' by assigning it a 'Title'.