For most editing of personal information, I usually have the tree view open. Each "card" has an Edit button on it, or right-click on the individual's "card". This will bring up a shortcut menu. The first option is to edit details for the person.
This is also true of the Marriage card - it has both an edit button and you may right-click to open the shortcut menu.
From the shortcut menu you can perform many different operations, including deleting the person. Pointing at each entry will open a further sub-menu of options.