We don't delete profiles. But you do have options.
1. As the other answer noted, if the person exists and has sources, you would click on the EDIT tab across the top and on the right hand side use the add/remove buttons to disconnect him from the family relationships. ie. if he is currently attached as a child to a set of parents (or spouse of someone), Click EDIT, then click the remove father button on the right, and on the page that comes up, go to the bottom, check the father's name and then hit Remove Father. Go back and do the remove steps - for the mother (or spouse).if needed
2. If he is just a mistake, not sourced, etc. then you would merge him into another profile. ie. if you entered Henry Holt born 1750, and you have a John Holt born 1762 - and you really want to 'get rid of ' Henry - change his name/dob to match another profile you created - to John Holt 1762 - and then merge the duplicate John Holt's.