When ever is used as an intensifier after how, what, when, where, or why, it should be separated by a space. Thus, how ever did you find her? could be rephrased, with no change of meaning, how did you ever find her? This rule tends to be more often followed—or more widely understood—in Britain than in the US. However in the sense of ‘no matter how’ (however gently you correct him, Peter always takes offense) should be spelled as one word. See also whatever (usage).