The MDM will walk you through the steps. The minute you remove the liquor tank from the machine - the machine knows...something is very, very wrong. Where’d the alcohol go? The display will ask if you are adding more of the same liquor or putting in something new? If it is a change in liquor, for example from vodka to rum, the MDM will flush out what liquor is left inside the basin. Be sure to have a cup ready.