LEDagent -
Gently pull the foam batt retainer off and find yourself a nice flat piece of steel. Hold the head firmly, and with hand pressure, you can just roll the back edge of the head at about a 45 degree angle on the steel. You are trying to roll the edge where the head thread end. Trying to wrap them a bit around the board that holds the positive battery contact. It really doesn't take much.
If it helps any - my EV died too. Since there aren't all that many EVs out, I wonder what the problem with them could have been?