Don't know about removing them without draining, but you can tell if the element is nominally within spec by shutting off power, disconnecting the leads from the element contacts, then using your ohmmeter, check for continuity through the element. Just like a lightbulb, if it is open, it is shot. If you could look up the specs, you might be able to determine the cold resistance value range, but the gross test of is it broken, is easy. My guess is that cold, you might see an ohm or so, but it will look very much like a short. Now, it would be 220*220/2500 = ~97 ohms for a 2500 watt element using 220v once hot, but you can't directly check ohms while hot.