The u-umlaut (often spelled "Muehl") is pronounced like ee with the lips in a whistling position, so it doesn't come out sounding like ee. (An o-umlaut sound is like a long a in English, again with the lips in a whistling position, so it comes out sounding different from a plain old English long a. As in Goethe.) There really is no equivalent sound in English, and Europeans know that, so they're usually satisfied when most Anglicizers just pronounce it as if there were no umlaut at all ("Muhl," or "Mule").